Yemeni police on Thursday arrested eight people suspected of planting a bomb that ripped through a market and injured 13 people on Wednesday, a police source said.

Police have not determined if any political or religious group was behind the explosion in the capital Sanaa, the source said. Three of the injured are in a critical condition.

Impoverished Yemen is struggling to quell a resurgent wing of Al-Qaeda which last month claimed responsibility for a plot to send two parcel bombs to the United States.

The southern Arabian Peninsula country is also facing violence from a separatist movement in its south while trying to cement a shaky truce with insurgent Shia rebels in the north.

Suspected militants from both Al-Qaeda and separatist groups have been accused of bombings and ambushes of state institutions or security forces, but bombings aimed at civilians are rare.