More than 130 Yemen rebels have been killed in air strikes south of Marib, a flashpoint of the civil war, the Saudi-led coalition said on Tuesday.

Dozens of strikes were carried out in the Abdiya district of Marib province. Marib city is the internationally recognised government's last outpost in northern Yemen.

"We targeted nine military vehicles of the Huthi militia in Abdiya, and their losses exceeded 134 members," said a coalition statement carried by official Saudi media.

Hundreds of Iran-backed Huthi rebels and military have died since fighting for the strategically vital city flared anew last month.

The Huthis warned they were "on the edges of the city", in a video statement released on Tuesday.

Rebel forces "today are on the edges of the city of Marib from several sides after defeating traitors and mercenaries... from several districts in Marib and liberating them completely," spokesman Yahya Saree said.

Yemen has been devastated by a seven-year conflict pitting the Shiite rebels against the government supported by a Saudi-led military coalition.

Tens of thousands of people have been killed and millions have been displaced since the conflict flared in 2014, when the Huthis seized the capital Sanaa.

The latest toll comes just a day after the coalition announced the deaths of 156 rebels in similar strikes in Abdiya. The rebels rarely announce casualties in their own ranks.

The Huthis renewed their campaign to capture Marib last month. The resulting clashes and air strikes have left hundreds of rebels and loyalists dead.

On Sunday, six people died in a car-bombing that targeted a convoy carrying the governor of Aden, the government's provisional seat of power. He survived the attack.

Prime Minister Maeen Abdulmalek Saeed called the Aden blast an "escalation" by the rebels.

"This is an escalation of violence by Huthi militias... a radical government in Iran is pushing the Huthis towards more violence," Maeen Abdulmalek Saeed told reporters in Cairo.