A NATO military commander confirmed on Friday that the alliance's aircraft bombed a rebel tank column near the oil town of Brega on Thursday.

"Two of our strikes yesterday may have result in deaths of a number of TNC (the Transitional National Council) forces who were operating in battle tanks. The incidence took place northeast of Brega," Rear Admiral Russell Harding said via video conference from Naples.

"The situation in this ares is still very fluid, with tanks and other vehicles moving in different directions, making it very difficult to distinguish who maybe operating them. In addition, until this time, we have not seen the TNC operating tanks," he said.

The bombing appeared to be the second friendly fire strike by NATO aircraft in less than a week. On Saturday, a NATO airstrike killed 13 rebel fighters near Brega, who were firing into the air to celebrate.

Harding said that the alliance's mission was to protect civilians in Libya and would remain impartial.

If the anti-Gaddafi forces threatened or attacked civilians, they would become targets of NATO strikes, he indicated.

NATO spokeswoman Oana Lungescu stressed on Friday that there was "no purely military solution" for the Libyan crisis.

"It is important to find a political solution ... There is no stalemate, just on the contrary, there is a clear drive from the international community to urgently find a political solution to this conflict," she told a press briefing.

The contact group on Libya, which is set up to provide political guidance for the military operation, is to convene on Wednesday in Doha, capital of Qatar.