Suicide bombings claimed by the Islamic State jihadist group have killed at least 142 people at mosques in the Yemeni capital, in an attack targeting Shi'ite worshippers including Huthi militiamen.

The multiple blasts yesterday were among the deadliest attacks yet in Yemen, which is grappling with growing instability and divisions along sectarian lines.

They came a day after clashes between forces loyal to President Abedrabbo Mansour Hadi and those allied with the Huthi Shi'ite militia in the southern city of Aden, where the leader fled last month.

The suicide bombers targeted two mosques attended by Huthis, who have seized the capital Sanaa.

One struck inside Badr mosque in southern Sanaa while another targeted worshippers as they fled outside, witnesses said.

A third suicide bomber targeted Al-Hashush mosque in northern Sanaa.

Nashwan al-Atab, a member of the health ministry's operations committee, told AFP that 142 people were killed and at least 351 were wounded.

The Huthi militia's Al-Massira television said hospitals in the capital had made urgent appeals for blood donations.

The imam of the Badr mosque was among the dead, a medical source said.

A Yemeni stands beside a car destroyed in the suicide attack. (AAP) (AAP)

Footage aired by Al-Massira showed bodies lying in pools of blood outside the mosques, as worshippers rushed the wounded to hospitals in pick-up trucks.

Another suicide bomber blew himself up outside a mosque in the northern Huthi stronghold of Saada, a source close to the militia said.

Only the assailant was killed in that explosion, and tight security at the mosque prevented the bomber from going inside, the source added.

In an online statement, the previously unknown Sanaa branch of IS claimed the bombings and said they were "just the tip of the iceberg".

"Infidel Huthis should know that the soldiers of the Islamic State will not rest until they eradicate them ... and cut off the arm of the Safavid (Iranian) plan in Yemen," the statement said.

IS, a radical Sunni Muslim organisation, considers Shi'ites to be heretics.

It is the first time that IS has claimed any attack in Yemen where al-Qaeda remains the most prominent jihadist group.

The Huthis overran Sanaa in September and have since tightened their grip on power.

Their attempts to extend their control into other areas have been met by deadly resistance from Sunni tribes and al-Qaeda.

Yemen, a front line state in the US war on al-Qaeda, has descended into chaos since the 2012 ouster of longtime strongman Ali Abdullah Saleh, who has been accused of backing the Huthis.