Libyan rebels are accusing the NATO coalition of mistakenly killing their fighters in a pair of air strikes. The rebels say at least four people were killed when NATO warplanes attacked an area near the town of Brega. Another six people are missing and feared dead. Fourteen others were wounded in the attack. NATO has refused to apologize for the strikes. The incident comes just days after rebel leaders sharply criticized NATO for what they said was a failure to stop the advance of forces loyal to Libyan leader Col. Muammar Gaddafi.