Canadian CF-18s were involved in action Wednesday that successfully pushed embattled Libyan leader Moammar Gadhafi's tanks back from the western city of Misrata.

Reports on the ground in the city of 400,000 said Gadhafi's soldiers were shooting civilians there last week.

The Canadian bombing reportedly destroyed an ammunition depot in the overnight operation.

Four laser-guided, 226-kilogram bombs were fired during the action, said Maj.-Gen. Tom Lawson, deputy chief of air staff.

"From all indications, it was a solid military target," Lawson said at a briefing in Ottawa.

There have been no reports of any civilians hurt or killed in the bombing, but Lawson said that "couldn't be assured until there was a full battle damage assessment."

The attacks are the first by Canadian aircraft in the UN-sponsored campaign to enforce a no-fly zone over Libya.

Four fighter-jets, supported by two air-to-air refueling aircraft, conducted two separate bombing runs, but officials said they had no information on the second bombing.

Tanks may return

One doctor on the ground fears that if the western bombing runs cease, the dictator's tanks will return.

The physician in Misrata says Gadhafi's tanks fled after the airstrikes began around midnight.

He says the bombs hit an aviation academy and a vacant lot outside the central hospital.

Meanwhile, the doctor told The Associated Press that bakeries have opened their doors for the first time in a week.

On Tuesday, two Canadian fighter jets took part in a mission but returned to base without attacking their target because the risk of "collateral damage was too great."

Lawson said the risk in that mission was not related to any threat to the CF-18s, but rather potential damage to civilians or important infrastructure such as hospitals, on the ground.

He added that the decision was in compliance with the rules of engagement that NATO forces have been given, and proves "the system works."

The Canadians who are working alongside their counterparts from France, the U.K. and U.S., has deployed a total of six CF-18s and the two CC-150 air-to-air refuelling planes to the Libya mission, as well as approximately 140 supporting Forces personnel from CFB Bagotville in Quebec.

Ottawa has also sent 25 additional personnel to Naples, Italy, to help co-ordinate the mission -- bringing Canada's total military contribution to more than 400 people.

The frigate HMCS Charlottetown has also been deployed to the region as part of a NATO humanitarian mission, following a pair of C-17 heavy-lift and two C-130J Hercules transport aircraft which were earlier dispatched to assist in evacuating Canadians from the troubled nation.

In total, Canada's military personnel contribution to the effort is more than 400 people.

Another half-dozen CF-18 fighters are on standby for deployment to the Mediterranean if needed by coalition forces.

With files from The Canadian Press