Sanaa, Oct 9 (IANS/EFE): At least 45 people were killed in a suicide bomb attack Thursday on supporters of the Shia Houthi movement in Yemen's capital Sanaa, the Houthis said.

In a statement, the Houthis said the explosion, which occurred as supporters were arriving for a demonstration at the capital's central Tahrir Square, also left 150 people injured, of whom 40 are in serious condition.

The toll has not been officially confirmed, but Spanish news agency Efe counted at least 20 bodies at the site of the explosion and it is possible that some of the wounded died later in hospital.

A suicide bomber set off the explosives-laden belt attached to his body near a security post in the central Tahrir Square where the Shias were holding a march against foreign intervention in Yemeni affairs.

No group has claimed responsibility for the attack, but for the past weeks the Al Qaeda has been running a campaign against the Shias and also attacking the military which it accuses of sympathising with the Houthis.

The explosion did not prevent thousands of supporters of the Shia "Ansar Allah" movement to continue their protests in Tahrir Square.

Leader of the group, Abdelmalek al-Houthi, accused the US Wednesday of having a hand in the appointment of Yemeni Prime Minister Ahmed ben Mubarak and called for demonstrations Thursday to reject his appointment.

Al-Houthi said in a televised speech Wednesday that Yemen's political forces had not reached a consensus on Ben Mubarak's appointment.

This consensus was one of the requirements of the peace agreement signed by the presidency and the Shia rebels Sep 21, which also calls for a cabinet including Houthi ministers.

Ben Mubarak resigned hours later "to protect national unity and avoid division".

A governmental committee, which supervises the political transition in Yemen, said that Yemeni President Abd Rabbuh Mansur Hadi had accepted the resignation.

But the Houthis decided to stage the demonstration anyway in protest against the alleged interference of the US in Yemen.

The Houthis have staged protests and have had armed clashes with security forces since last August, and even seized control of parts of Sanaa and its government buildings.

Former prime minister Mohammed Salem Basendwah quit his post Sep 21 following mass protests against him and his government that lasted more than a month.