Forces advance in IS bastion as US keeps up air strikes

US President Barack Obama defended the two-day-old air campaign, saying defeating the jihadists there was in America's national interest.

The IS bastion, located just across the Mediterranean from Europe, has been shaken by weeks of fierce clashes between jihadists and fighters allied to Libya's UN-backed Government of National Accord (GNA).

The city, 450 kilometres (280 miles) east of Tripoli, has been controlled by IS since June 2015, and its loss would be a major blow to the jihadists, who have faced a series of setbacks in Syria and Iraq.

Forces loyal to the Tripoli-based GNA said Tuesday they had gained full control of Al-Dollar, a central residential district in Sirte, after clashes that killed five of their members and wounded 17.

The announcement came after US aircraft launched five air strikes on Monday against "several targets in Sirte, hitting IS members and vehicles", the GNA forces said in a statement.

"It is in America's national security interest in our fight against ISIL to make sure (the GNA are) able to finish the job," Obama told a White House news conference, using an IS acronym.

- New air raids -

"We're working in partnership with them to assure that IS does not get a stronghold in Libya, even as Libya begins what is going to be a long process to establish a functioning government and security system," the president said.

Pentagon spokesman Navy Captain Jeff Davis said the United States had conducted seven strikes so far: five on Monday and two on Tuesday.

Two T-72 tanks were among the targets, and Davis said IS fighters had been killed, but he did not have an estimate of how many.

While the Pentagon had conducted two previous air attacks on high-value IS targets in Libya since last year, Monday's action marked the first US strikes in Sirte itself.

The GNA press office said Tuesday that the latest strikes had destroyed an IS rocket launcher and a vehicle.

IS has taken advantage of the chaos in Libya after the 2011 ouster of longtime dictator Moamer Kadhafi to increase its presence in the oil-rich country.

The jihadists have claimed deadly attacks, including beheadings, and targeted foreign embassies.

Sarraj's unity government emerged as the result of a UN-brokered power-sharing deal in December, but it has struggled to assert its authority across Libya.

A rival administration based in the country's far east has refused to cede power to Sarraj's government since he sailed into the capital under naval escort in March.

- 'Limited' strikes -

More than 300 pro-GNA fighters have been killed and over 1,500 wounded since the start of the battle for Sirte, according to medical sources.

Forces supporting Sarraj's government entered Sirte on June 9, but their advance has been slowed by an IS fightback using suicide car bombs and sniper fire.

The pro-GNA forces are mostly made up of militias from western Libya established during the 2011 revolt.

Sarraj said the American involvement would be "limited in time and will not go beyond Sirte and its suburbs".

The Libyan parliament however, which does not back the GNA, branded the US strikes a "violation of (Libyan) airspace", according to a news agency that is close to the legislative body.

The foreign ministry in Russia, which is carrying out anti-IS strikes in Syria at the request of the Damascus regime, stressed the need for "close coordination (in) the efforts of all countries engaged in the battle against terrorism".

The American raids were carried out at the request of Libyan authorities, it noted.

Foreign Minister Paolo Gentiloni of Italy, Libya's former colonial ruler, spoke to Sarraj by phone on Tuesday and expressed Rome's appreciation for the GNA's "commitment against terrorism", a statement said.

France reaffirmed its "full support" for Libya's unity government, while at the same time seeking to mend fences over the presence of French troops in the east of the conflict-ridden country.

Prime Minister Jean-Marc Ayrault, also speaking to Sarraj by telephone, "hailed the decision of the Libyan authorities to appeal for international aid", the foreign ministry in Paris said.

Paris recognises the GNA, but it also supports anti-IS forces loyal to the parliament and government based in the east that are refusing to cede power to the UN-backed administration.

Military sources in the east said a suicide bomber on Tuesday killed at least 15 soldiers loyal to the non-recognised government in an attack in the city of Benghazi claimed by a militia alliance, the Revolutionary Shura Council.