Mustafa Abdel Jalil, the head of Libya's ruling National Transitional Council (NTC), warned on Sunday the country could be heading towards a bottomless pit after protesters stormed a government office in Benghazi when he was inside.

A crowd demanding the resignation of the Libyan government smashed windows and forced their way into the NTC's local headquarters late on Saturday, in the most serious show of anger at the new authorities since Muammar Gaddafi was ousted.

The NTC has the support of the Western powers who helped force out Gaddafi in a nine-month conflict, but it is unelected, has been slow to restore basic public services, and some Libyans say too many of its members are tarnished by ties to Gaddafi.

Speaking to reporters at a hotel in Benghazi, Abdel Jalil warned the protests risked undermining the country's already fragile stability.

We are going through a political movement that can take the country to a bottomless pit, he said. There is something behind these protests that is not for the good of the country.

The people have not given the government enough time and the government does not have enough money. Maybe there are delays, but the government has only been working for two months. Give them a chance, at least two months.

The protests in Benghazi, in eastern Libya, are particularly troubling for the NTC because the city was the birthplace of the revolt against Gaddafi's 42-year rule. It was the site of the NTC's headquarters during the revolt.

Abdel Jalil said he met with religious leaders and protesters to discuss their grievances.

He said he had accepted the resignation of the head of the Benghazi local council, Saleh El-Ghazal. Like most Libyan officials, the head of the council was appointed but Abdel Jalil said his successor would be chosen through an election.

Abdel Jalil said that later on Sunday he will unveil a law on elections for a national assembly, which are scheduled to take place within about six months.

Libya's leaders hope the law will ease some of the tension by setting out a clear road-map for the replacement of the NTC with an elected body.

(Additional reporting by Taha Zargoun in Tripoli and Mohammad Al Tommy in Benghazi; Writing by Christian Lowe; Editing by Sophie Hares)