Deadly clashes raged Sunday around Libya’s main international airport, closing in down, as militiamen attacked liberal rivals in their Tripoli bastion, in an intensifying power struggle.

Deadly clashes raged Sunday around Libya's main international airport, closing in down, as militiamen attacked liberal rivals in their Tripoli bastion, in an intensifying power struggle.

A health ministry spokesman, speaking on condition of anonymity, said at least six people were killed and 25 wounded in the clashes.

It was not immediately known if civilians were among the casualties.

Exchanges of fire with heavy weapons forced the closure of Tripoli airport, as foreign ministers from the North African nation's neighbors were to meet later in Tunisia to consider how to aid chaos-riddled Libya.

The assault on the Zintan group by rival militants also came after the UN pulled staff from Libya citing security reasons, and as the United States warned of further escalation.

An airport official said "rockets struck inside the airport perimeter around 6 am (0400 GMT)", followed by heavy clashes between the Zintan militia which controls the airport and rival gunmen.

An airport source said Zintan fighters pushed back the assailants but that clashes continued to rage around the facility, as locals reported seeing tanks deploy and smoke billowing.

Authorities closed the airport for at least three days from Sunday after initially halting flights.

Sunday's attack was claimed by the Operations Cell of Libyan Revolutionaries, a coalition of militias seen as the armed wing of extremists within the General National Congress or parliament.