A senior United Nations official for Libya has condemned the storming of the parliament’s headquarters by angry demonstrators as part of protests in several cities against the economic turmoil and the political deadlock in the country.

Hundreds of protesters marched in the streets of the capital, Tripoli, and other Libyan cities on Friday, with many attacking and setting fire to government buildings, including the House of Representatives in the eastern city of Tobruk.

“The people’s right to peacefully protest should be respected and protected but riots and acts of vandalism such as the storming of the House of Representatives headquarters late yesterday in Tobruk are totally unacceptable,” Stephanie Williams, the UN special adviser on Libya, posted on Twitter on Saturday.

“It is absolutely vital that calm is maintained, responsible Libyan leadership demonstrated, and restraint exercised by all.”

Friday’s protests came a day after the leaders of the parliament and another legislative chamber based in Tripoli failed to reach an agreement on elections during UN-mediated talks in Geneva. The dispute now centres on the eligibility requirements for candidates, according to the UN.

Libya failed to hold elections in December, following challenges such as legal disputes, controversial presidential hopefuls and the presence of rogue militias and foreign fighters in the country.

The failure to hold the vote was a major blow to international efforts to bring peace to the Mediterranean nation. It has opened a new chapter in its long-running political impasse, with two rival governments now claiming power after tentative steps towards unity in the past year.

Interim Prime Minister Abdulhamid Dbeibah leads a Tripoli-based administration while former Interior Minister Fathi Bashagha draws support from the Tobruk-based House of Representatives and military renegade Khalifa Haftar.

Fragile situation

Protesters have also rallied against dire economic conditions in the oil-rich nation, where prices have risen for fuel and bread and power outages are a regular occurrence.

Libya’s energy sector has also fallen victim to political divisions, with a wave of forced closures of oil facilities since April.

Supporters of the eastern-based administration have shut off the oil taps as leverage in their efforts to secure a transfer of power to Bashagha, whose attempt to take up office in Tripoli in May ended in a swift withdrawal.

People hold a banner that reads ‘The exit of all foreign forces in the east and west of the country’ in Tripoli, Libya

Libya’s National Oil Corporation has announced losses of more than $3.5bn from the closures and a drop in gas output, which has a knock-on effect on the power grid.

Recent weeks have seen repeated skirmishes between armed groups in Tripoli, prompting fears of a return to full-scale conflict.

Sabadell Jose, the European Union envoy in Libya, called on protesters to “avoid any type of violence”. He said Friday’s demonstrations demonstrated that people want “change through elections and their voices should be heard”.

Libya has been racked by conflict since a NATO-backed uprising toppled and killed longtime ruler Muammar Gaddafi in 2011.

The country was then for years split between rival administrations in the east and the west, each supported by different armed groups and foreign governments.