TRIPOLI (REUTERS) - Three children, all sisters, were killed and a woman and child wounded in an air strike that hit a residential district in the Libyan capital on Monday (Oct 14), a Reuters reporter and the Tripoli government said.

The wounded woman was in critical condition and the injured girl had emergency surgery to amputate a leg, the Tripoli-based Health Ministry said in a statement.

Libya's internationally recognised government blamed the strike on forces of Khalifa Haftar, the commander based in the east of the North African country who has been trying to seize Tripoli in the west in a ground and air campaign since April.

The spokesman for Haftar's forces, Ahmed Mismari, denied his forces had carried out an air strike on a house in the Fornaj district in southern Tripoli.

A Reuters reporter saw a heavily damaged two-storey house and saw the bodies of the three sisters in a morgue.

The conflict in and around the capital has killed and wounded hundreds of civilians and more than 120,000 have been displaced, but Haftar's offensive has not breached the city's southern defences.

Germany unveiled plans last month for a UN-backed conference in an attempt to enforce a ceasefire and have regional actors agree to stop arming the warring sides.

Haftar is backed by Egypt and the United Arab Emirates, while Turkey supports the Tripoli government.

Libya has been in turmoil since the rule of leader Muammar Gaddafi was brought to an end in a NATO-backed uprising in 2011.