An air raid hit the criminal investigations unit in Yemen's rebel-held capital Sanaa on Sunday as insurgents battle the government, backed by a Saudi-led coalition, for control of the country. The four-storey building and a line of police cars parked outside were largely destroyed in the attack.

A Saudi-led coalition air strike hit Yemen's rebel-controlled state television station in Sanaa overnight, killing four guards, rebel media and the head guard said on Saturday.

The war-torn Arabian Peninsula country has been plunged deeper into turmoil by the killing on Monday of ex-president Ali Abdullah Saleh by the Houthis.

Thousands of Houthi supporters rallied in Sanaa on Tuesday as the rebels cemented their grip on the Yemeni capital after killing their former ally ex-president Ali Abdullah Saleh.

The head of the Arab League warned that Saleh's killing following the collapse of his uneasy alliance with the rebels threatens an "explosion in the security situation" in the war-ravaged country.

Humanitarian aid workers arrived in the Yemeni capital of Sanaa on Saturday, after a nearly three week blockade by the Saudi-led military coalition, an official at the UN's World Food Programme (WFP) said.

Yemen's rebel government on Tuesday announced the country's main international airport was fully functional again, one week after a Saudi-led air strike destroyed the facility's navigation system.

Yemen's Houthi rebels, who are locked in a deadly war with the Saudi-supported government, on Sunday said they had downed a drone on the northern outskirts of the country's capital.

Warplanes attacked a checkpoint outside the Yemeni capital Sanaa on Wednesday, killing five civilians in a taxi and two armed personnel manning the site, witnesses said.

Gunmen from both groups in a strained civil war alliance withdrew from streets in the Yemeni capital on Sunday after trading fire in unprecedented violence, officials from the two groups said.

An air strike on Yemen's capital Sanaa killed 12 people including six children on Friday, rescuers said. The attack on the Faj Attan area on the outskirts of the city also severely damaged at least two buildings, reducing much of them to rubble, they said.

The rally marking 35 years since the founding of Saleh's Arab nationalist General People's Congress (GPC) sends out a signal that the strongman remains a force to be reckoned with.