A strike originating from Libya's official government killed at least eight civilians while its soldiers also shot down a warplane by its Tripoli-based rivals, it was reported on Monday.

The attacks come as the UN special envoy to Libya, Bernardino Leon, is attempting to broker a ceasefire in Brussels. The North Africa country is split between governments based in the capital, Tripoli, and the eastern city of Tobruk.

Libya has had two governments and parliaments since Tripoli was seized in August 2014 by Fajr Libya, a militia alliance which includes Islamists that has installed its own government and legislature.

Leon said that negotiations towards establishing a unity government were progressing.

"There is a chance that we can make progress and have first names for a unity government this week," Leon said in Brussels.

The conference includes Libyan mayors in an attempt to establish contacts between rival factions.

"It is going to be a difficult discussion and I wouldn't like expectations to be too high, bearing in mind how difficult the situation is on the ground,” Leon said.

Government presses on with assault to recapture capital

War planes belonging to the internationally-recognized government in Tobruk attacked the town of Tarhouna, controlled by its rivals.

Eight civilians were killed in the strike, according to a tweet by the U.S. Ambassador to Libya, Deborah Jones.

"This violence serves no one's interests," wrote Jones who is currently outside the country.

Army spokesman Ahmed al-Mesmari claimed the elected government had targeted an Islamist militia in the strike. He said the strikes prompted retaliatory attacks that killed four civilians, including a woman whose hands were cut off.

Meanwhile, the internationally-backed government claims it shot down a warplane piloted by its rivals in Tripoli. Government spokesman Mohammed al-Masri said the plane was downed Monday after it bombed Zintan, a mountainous town loyal to the elected government.

Reports of causalities were not available.

But the tit-for-tat airstrikes underscore the difficulty lying ahead for the European mediations.

"These mayors are courageous," Leon told reporters. "We have cities that have been bombed in recent days, have suffered terrorist attacks in recent days."

European leaders seek to end the incessant fighting that followed the 2011 NATO-supported military intervention that brought down strongman Moammar Gadhafi, who had ruled Libya for decades.

Since his ouster, the oil-rich nation has been divided by rival factions and has become a bridgehead for the Islamic State militant group, as well as a launching pad for migrants seeking to cross into Europe illegally.

"It's an international challenge. That is why our work is so important," said EU foreign policy chief Federica Mogherini, a former foreign minister of Italy, Libya's former colonial ruler.

jar/jr (Reuters, dpa, AP)