Rebels in eastern Libya said Thursday that more than 10 of their fighters were killed in a NATO airstrike, as they continued to battle against leader Moamer Gaddafi's forces for key cities, dpa reported.
The NATO attack took place between the rebel-held city of Ajdabiya and the strategic oil port of Brega, where the opposition has been fighting Gaddafi's troops for several days.
"We are looking into it ... it is difficult for us to establish the facts because we have no boots on the ground," a NATO official told the German Press Agency dpa.
Earlier Thursday the rebels said they had made some headway into Brega, but were unable to secure the eastern city by nightfall.
The Libyan opposition told dpa that the rebels mistakenly entered a zone, between Ajdabiya and Brega, which NATO had previously targeted. The alliance's planes apparently mistook the rebels' vehicles for those of Gaddafi's forces.
A week back, NATO jets accidentally attacked a rebel position in the same area, leaving 13 dead and 11 wounded. That assault came after the rebels shot celebratory gun shots in the air, that were mistaken for gunfire from Gaddafi's men.
Meanwhile, the Paris-based Reporters Without Borders said Thursday that four foreign journalists - two Americans, one South African and one Spaniard - have gone missing in eastern Libya.
In the west of the country, Gaddafi's forces continued to fire rockets near the village of Yefren, according to opposition website Libya al-Youm.
In the northwestern city of Misurata, NATO fighter jets shelled Gaddafi's brigades, residents told Libya al-Youm.
Misurata, the third-largest city and a key battleground en route to the capital Tripoli, has witnessed pitched battles for more than 40 days.
The rebel's military leader and former interior minister, Abdul Fattah Younis, said Misurata's residents are without medical supplies, water and electricity and have only light weapons for self- defence.
"Misurata is facing annihilation," Younis warned. He lashed out at NATO for not moving quickly enough to stop Gaddafi's attacks.
NATO has rejected the criticism, saying the pace of its operations continues unabated.
French Foreign Minister Alain Juppe said Thursday that the next meeting of a contact group set up to guide the international intervention in Libya will meet in Qatar on April 13.
Foreign Minister Guido Westerwelle said Germany was having second thoughts about its refusal to get militarily involved in the Libyan crisis, and that it might send forces to help evacuate refugees.
A UN World Food Programme (WFP) ship carrying food, medical supplies and with two doctors on board, arrived Thursday in Misurata.
"This is a breakthrough for the UN humanitarian operation in Libya and allows us to reach tens of thousands of people who are caught in one of the fiercest areas of conflict," the Rome-based WFP's executive director, Josette Sheeran, said in a statement.
"It is vital that we get these relief supplies to the vulnerable - especially women and children - and we are working with local partners, including the Libyan Red Crescent, to ensure their needs are met," she said.
The WFP-chartered vessel, Marianne Danica, was carrying more than 600 tons of wheat flour, vegetable oil and high-energy biscuits, which according to WFP is enough to feed more than 40,000 people for a month.
The ship is also delivering medical supplies on behalf of the UN's children aid agency, UNICEF, and the World Health Organization.
These included emergency health kits and surgical material that will cover the needs for 50,000 people for a month, WFP said.