A hospital physician in Misrata says Libyan government forces are pounding the outskirts of the rebel-held city and have so far killed at least 22 people.

The doctor at Hikma Hospital, who would only give his first name, Ayman, said Muammar al-Qaddafi's forces were using tanks, artillery and incendiary rockets in the bombardment of Dafniya, about 18 miles west of Misrata. He said at least 61 people were wounded. The attacks began about 10 a.m. local time Friday.

Rebels tell Reuters that pro-Qaddafi forces shelled their positions in the Western Mountains region.

"They are shelling Zintan with Grad missiles. There have been no NATO air strikes for a week," a rebel spokesman told Reuters.

This latest violence comes as Norway says it will scale down its fighter jet contribution in Libya from six to four planes and withdraw completely from the NATO-led operation by Aug. 1.

Defense Minister Grete Faremo said she expects understanding from NATO allies because Norway has a small air force and cannot "maintain a large fighter jet contribution during a long time."

The Scandinavian country's air force says Norwegian F-16 jets have carried out about 10 percent of the NATO airstrikes in Libya since March 31.

The parties in the center-left coalition government had been at odds over whether to extend the Norwegian mission, which was scheduled to expire June 24. The most leftist faction in the government, the Socialist Left Party, opposed an extension but a compromise was reached to stay in the operation until Aug. 1 with fewer planes.

"It is wise to end the Norwegian fighter jet contribution. Now Norway should apply its efforts to find a peaceful solution in Libya," Socialist Left Party lawmaker Baard Vegar Solhjell said.

While Norway announces the end of its involvement in Libya, the Dutch government extended its forces' role in the NATO campaign of air strikes in Libya until the end of the three month extension the alliance recently announced.

U.S. Defense Secretary Robert Gates this week urged NATO allies including the Netherlands to do more in Libya to share the burden with France and Britain, which are carrying out most of the air strikes.

The Dutch government, however, is still refusing to let its six F-16 fighter jets involved in the mission to carry out airstrikes. Instead they will continue to enforce the no-fly-zone above Libya.

In addition, the government announced Friday it will send experts in psychological operations and legal affairs to join the mission.

NATO denied Friday a Libyan state television report that one of its helicopters was shot down in the sea.

The Associated Press contributed to this report.