Japanese officials are conceding the core of a damaged reactor at the Fukushima Daiichi nuclear power station may have cracked. Nuclear safety officials say a probe is underway to determine the source of the leak that has emitted dangerous levels of radiation and raised fears of contaminated food and water supplies. Two workers at the plant were hospitalized on Thursday after stepping in contaminated water. The water had 10,000 times the amount of radiation normally found in water from a functioning reactor. The official death toll from the Japanese earthquake and tsunami has passed 10,000, with more than 17,000 missing.

The ongoing crisis in Japan comes as a new federal report is calling into question the self-regulatory practices of nuclear plants in the United States. According to the U.S. Nuclear Regulatory Commission’s inspector general, over a quarter of U.S. nuclear power plants have failed to properly report equipment defects that could threaten the safety of their reactors. At least 28 percent of the nation’s 104 nuclear plants appeared unaware of rules requiring their disclosure of any safety flaws, even if no actual lapses occur. Experts say the lack of disclosures could make it more difficult for nuclear operators to uncover flaws in the equipment they have in common with other facilities.

NATO countries have agreed to join the military intervention in Libya. On Thursday, NATO Secretary-General Anders Fogh Rasmussen’s said the military alliance’s mandate will be kept to enforcing the no-fly zone over Libyan airspace “to protect civilians.”

NATO Secretary-General Anders Fogh Rasmussen: ”NATO allies have now decided to enforce the no-fly zone over Libya. We are taking action as part of the broad international effort to protect civilians against the attacks by the Gaddafi regime. We will cooperate closely with our partners in the region, and we welcome their contributions.”

NATO could engage with Libyan forces in self-defense against attacks. Rasmussen’s statement appeared to contradict earlier comments by Turkey’s foreign minister, who said NATO would be taking control of all military operations in Libya from the U.S.-led international coalition.

Around 336,000 people have fled Libya since clashes erupted between rebels and Libyan leader Col. Muammar Gaddafi’s forces. The death toll is unknown but is estimated to be in the thousands. At the United Nations, Secretary-General Ban Ki-moon said the Gaddafi regime remains in violation of international calls for a ceasefire.

U.N. Secretary-General Ban Ki-moon: “Libyan authorities have repeatedly claimed that they have instituted a ceasefire, including in a call to me by the prime minister of Libya on 19 March. We see no evidence that is the case. To the contrary, fierce battles have continued in or around the cities of Ajdabiya, Misurata and Zintan, among others. In short, there is no evidence that Libyan authorities have taken steps to carry out their obligations under Resolutions 1970 or 1973.”

The Gaddafi regime continues to attack rebel-held towns in Libya. In the opposition stronghold of Benghazi, a Libyan rebel leader urged the international community to provide weapons to the uprising.

Col. Ahmed Bani: “In fact, we need support. We need support on this subject, especially. And, you know, our friends, they are trying now to support us, and I hope that soon, soon, we will succeed, and we will have all that weapons that can help us to liberate the whole Libya, Insha’Allah.”

The Gaddafi regime continues to claim the U.S.-led bombing campaign has killed scores of civilians. A Libyan government spokesperson said around 100 civilians have died in Western air strikes and accused the U.S.-led coalition of seeking to bomb non-military targets including phone towers and broadcasting stations.

Musa Ibrahim: “These are civilian targets. Broadcasting, whether it’s radio or TV, communications, whether it’s phones or other uses, are all civilian, and they are for the good of the Libyan nation. But we are getting close to a hundred, that’s for sure.”

Reporter: “Civilians?”

Musa Ibrahim: “Yes. I’ve asked the minister for health to be with you tomorrow. I’m going to—he is an extremely busy man, I can understand why.”

Protesters in Syria are gearing up for another day of massive demonstrations today despite a pledge from the Syrian government to enact reforms. On Thursday, a spokesperson for Syrian President Bashar al-Assad said the government would review a longstanding emergency law and consider allowing political opposition groups. The pledge came as more than 20,000 people rallied in the city of Daraa, where state forces killed at least 25 people earlier this week.

Hundreds of thousands of people have reportedly flooded the streets of the Yemeni capital city of Sana’a today in the growing uprising against U.S.-backed President Ali Abdullah Saleh. Opposition activists have rejected Saleh’s offer to step down by the end of the year and provide amnesty to defecting soldiers.

Protester: “We ask the President to leave and give up his authority in order to avoid bloodshed, because the people will continue to revolt until this regime falls.”

Today’s protests come one week after 52 demonstrators were killed by pro-Saleh forces.

Pro-democracy activists in Jordan have established a tent camp in the capital city of Amman modeled after Egypt’s Tahrir Square. More than 1,000 people set up the encampment Thursday night, calling themselves the “March 24th Movement” after the date their action began. The tent camp could re-spark a wave of protests that broke out inside Jordan earlier this year.

The U.S.-led NATO force in Afghanistan has issued another apology for the killing of Afghan civilians. NATO says two civilians were accidentally killed in an air strike on Wednesday in the province of Khost. Two children were killed in another NATO attack last week, and nine boys died in another attack earlier this month.

Wisconsin’s anti-union bill is headed to the state Supreme Court after a lower appeals court declined to weigh in. The state has appealed last week’s decision by a Wisconsin state judge to issue a temporary restraining order blocking the measure’s implementation. The judge ruled that Republican lawmakers were likely in violation of the state open meeting laws when it pushed through the legislation earlier this month.

An Indiana prosecutor has resigned after acknowledging he advised Republican Gov. Scott Walker of Wisconsin to stage a physical attack on himself and blame it on protesters. In an email to Walker, the prosecutor, Carlos Lam, wrote: “If you could employ an associate who pretends to be sympathetic to the unions’ cause to physically attack you (or even use a firearm against you), you could discredit the public unions.” Lam has been active in the Republican Party in Indiana. He initially denied authoring the email on Thursday before admitting to it and submitting his resignation.

Republican lawmakers in Ohio and Texas have advanced controversial voter identification measures that critics say will discriminate against people of color. The Ohio measure would restrict acceptable documents for in-person voting to five types of identification. Ohio residents would no longer be allowed to present documents including bills, bank statements, or even government documents. Students would no longer be allowed to use college IDs. The Texas measure would also force residents to present valid photo identification such as a driver’s license, passport, military ID, or state ID in order to vote.

Thousands of people rallied at the Georgia State Capitol in Atlanta against an immigration bill similar to the Arizona measure passed last year. The legislation would mandate law enforcement officers to check the immigration status of suspects if officers believe they have “probable cause.”

The U.S. Department of State has reversed a decision to deny a travel visa to Afghan women’s and democracy activist Malalai Joya. In 2005, Joya became the youngest person ever elected to the Afghan parliament. She was suspended in 2007 for her denunciation of warlords and their cronies in government. Joya had planned a three-week U.S. tour to promote a new edition of her memoir when she was barred earlier this month. The decision was reversed after the State Department came under heavy protest. Joya is scheduled to speak with MIT Professor Noam Chomsky tonight in Boston.