TRIPOLI, Libya - NATO warplanes on Saturday struck a missile launching position that Libyan ruler Moammar Gadhafi's forces used to target the civilians in western Libya, the alliance said in a statement.

Government troops used the missile site outside the rebel-held port city of Misrata to fire indiscriminately on civilians in the area, NATO said.

Since the uprising against Gadhafi's 42-year rule broke out in February, armed rebels saying they seek democracy have seized much of the country's east, where they've set up an administration in the city of Benghazi. They also control much of the western Nafusa mountains and Misrata, Libya's third largest city.

The civil war, however, has fallen into a stalemate, with rebels unable to make significant advances, even with NATO bombing Gadhafi's forces to enforce a U.N. resolution protecting civilians.

Misrata's rebels, struggling to advance on Tripoli, have faced stiff resistance from government forces.

The British military says it scuttled an effort by Gadhafi's naval forces Friday to conduct a raid near Misrata by firing on the troops' boats from a warship offshore.

Also on Saturday, the International Organization for Migration said it was airlifting about 2,000 stranded migrants out of the southern Libyan town of Sebha.

Spokesman Jean-Philippe Chauzy said the majority of those stuck in Sebha are economic migrants from Chad, Libya's impoverished southern neighbour, and lack the money or health to cross the desert to their home country.

"They are really very vulnerable migrants -- children, women and the elderly -- very weak and sick," he said. "They are those who didn't make it further south than Sebha because they didn't have the strength."

The first of about a dozen flights to get them out left Thursday. The last will be in a week or two.

Between 1.5 and 2 million migrants were estimated to be in Libya before the war. The IOM has evacuated close to 150,000 so far, Chauzy said. About 300,000 are believed to remain, he said, either because they can't get out or because they've chosen to stay rather than return to their impoverished homelands.