NATO relief ships arrive in Libya

>> we turn to libya and the news from there tonight. after a two-day extension over the weekend, u.s. military officials now tell nbc news american war planes tonight are really going to end their air strike mission against moammar gadhafi 's military targets but they will continue to fly what they call support missions for nato aircraft.

>>> meanwhile, libyan rebels and gadhafi 's forces are in a standoff tonight in the strategic oil town of brega today. our chief foreign correspondent richard engel traveled there and back. he's now back in benghazi where he joins us tonight. richard, good evening.

>> reporter: good evening, brian. that support mission remains very significant here. it means u.s. aircraft will be refuelling other jets, collecting intelligence and if specifically requested by another nato partner flying combat missions as well. the front line on the desert highway outside brega can change in seconds. gunfire by gadhafi 's troops forces the rebels into a rapid retreat. but later the rebels return, launching surface-to-surface rockets. here on the front lines the rebels and gadhafi 's forces, separated by a few miles, have reached a stalemate. for the last several days, neither has advanced or retreateretreat ed more than a couple hundred yards. the stalemate is frustrating to the rebels . the nato air strikes aren't as frequent as before.

>> why slow, slow be no help for me any? why?

>> reporter: so the rebels are getting creative about boosting their firepower, even attaching aircraft rocket launchers to pickups. if it doesn't fire we'll club gadhafi over the head with the rockets, a rebel said. nato is allowing aid to reach the people. two ships ferried hundreds of people to turkey and tunisia. nearly all are from misrata in libya which remains surrounded by gadhafi 's troops who are allegedly brutalizing people.

>> there is rape. there is beating.

>> reporter: but in benghazi , the city saved by western intervention, today a rally to complain that nato isn't doing enough to help the rebels defeat gadhafi . demonstrators in benghazi said they are not interested in a political compromise being floated in tripoli in which gadhafi 's sons would take over and then transition to democracy . people here think it's simply not credible, brian.

>> richard engel back in benghazi , libya , for us. richard, thanks.