Southern district of Abu Salim in the capital got shelled late on Tuesday, killing four and wounding at least 20.

At least four people have been killed in heavy shelling in the Libyan capital Tripoli.

Nearly two weeks into the assault to seize the city, Khalifa Haftar‘s eastern-based Libyan National Army (LNA) is stuck in the city’s southern outskirts battling armed groups loyal to the UN-recognised Tripoli government.

But the southern district of Abu Salim got shelled late on Tuesday with explosions heard even in the city centre where life had been going on largely untouched by the violence in Libya.

The artillery killed at least two people and wounded eight, Osama Ali, spokesman for a Tripoli emergency body, told Reuters news agency, without saying who was behind the shelling.

Another official told Libya Al Ahrar TV channel four people were killed and 20 wounded.

The district is located near the road to the old airport in southern Tripoli, which has changed hands several times since the fighting started.

Abu Salim lies north of forces loyal to the Tripoli government seeking to stop the LNA troops coming from the south.

Forces allied to Tripoli have accused the LNA of firing rockets into residential areas, but the LNA said in a statement it had nothing to with the shelling, accusing a Tripoli-based group instead .

Al Jazeera’s Mahmoud Abdelwahed, reporting from Tripoli, said it was not the first time Haftar’s forces targeted civilian areas.

“Many people here are also wondering why the international community is not putting pressure on Haftar to stop the escalation in and around the capital Tripoli,” he said.

Libya, which has been mired in chaos since the NATO-backed toppling of Gaddafi in 2011, has been split into rival eastern and western administrations since 2014.

In March 2016, Government of National Accord (GNA) chief Fayez al-Sarraj arrived in Tripoli to set up a new government, but the Haftar-allied administration in the eastern city of Tobruk refused to recognise its authority.

Haftar’s push on the capital threatens to further destabilise the oil-rich country and reignite a full-blown civil war. Both sides accuse each other of targeting civilians.

At least 174 people have been killed and 756 wounded since the LNA started its offensive on April 4, according to the World Health Organization. It says it has deployed additional surgical staff to support hospitals receiving trauma cases.

As the rockets fell on Tuesday, UN Security Council diplomats began negotiations on a British-drafted resolution that would demand an immediate ceasefire in Libya.

The proposed text, seen by AFP news agency, warns that the offensive by Haftar’s LNA “threatens the stability of Libya and prospects for a United Nations-facilitated political dialogue and a comprehensive political solution to the crisis”.

The council “demands that all parties in Libya immediately de-escalate the situation, commit to a ceasefire, and engage with the United Nations to ensure a full and comprehensive cessation of hostilities throughout Libya”, the draft says.