Former Libyan energy minister Omar Fathi bin Shatwan, who also served as Libya's industry minister, has fled by fishing boat to Malta from the western Libyan city of Misrata, the Associated Press is reporting.

It said he came to Malta last Friday.

Mr Shatwan is a former chairman of the Libya-Malta mixed commission and left the government in 2007.

He told AP that several members of Muammar Gaddafi's inner circle want to defect, but are too scared to do so — in some cases, their families are under siege, he said.

"Those whose families are outside Libya will flee if they get a chance," Shatwan said in a telephone interview. "But many can't leave, and all the families of ministers are under siege," he told AP.

Shatwan said he last had contact with Gaddafi in 2006, and had not spoken with the tyrant's sons.

He said he spent 40 days bunkered down at his home in the central port of Misrata before escaping from Libya, and witnessed Gaddafi's forces pounding the city with heavy artillery and relentlessly shooting civilians.

"There has been a big bombardment and there is total destruction," Shatwan said. "After this, they occupied some streets with tanks, and put snipers in the buildings."

"I think the regime is just going mad," he said. "Col. Gaddafi has changed. No one would kill people in the streets in this way. Not even Hitler did that."

He estimated at least 1,500 people are dead or wounded in Misrata, but said it is almost impossible to know the exact figure as many people are missing.

The ex-minister urged NATO to step up its military campaign.

"The West should act quickly to finish the job, before there are a lot more people dead," he told the AP.