Gunmen on a motorbike shot dead a top official of the Shia Huthi militia in the Yemeni capital on Wednesday, a security source said.

Abdul Karim al-Khiwani, a member of the Revolutionary Committee of the Huthis who control Sanaa, was attacked by two gunmen, the source said.

The Huthis' television channel Al-Massira confirmed the report.

Khiwani was shot close to his home, the source said.

He had represented the Huthis' Ansarullah movement during national talks stipulated by a UN-backed peace agreement that ended a year of deadly protests against President Ali Abdullah Saleh, who stepped down in February 2012.

The talks concluded in January last year with a plan to turn the republic into a federation of six regions -- a blueprint that the Huthis strongly opposed.

The Huthis have been in effective control of Sanaa since September, expanding their zone of control to neighbouring regions and to the shores of the Red Sea.

President Abedrabbo Mansour Hadi escaped last month from house arrest in Sanaa and has fled to second city Aden in the south, where he is attempting to re-establish authority.