KABUL, March 14 (Xinhua) -- A suicide blast killed six civilians, injured 31 persons in Khost city, capital of Khost province in eastern Afghanistan, on Wednesday afternoon, spokesman of provincial governor told Xinhua.

    A suicide bomber blew himself up before a police convoy in the city at around 2:50 p.m. (1020 GMT), killing six persons and wounding 31 others including three policemen, Salim Camran said.

    No group or individuals have claimed responsibility, but the Taliban has frequently carried out similar attacks before.

    Early on Wednesday, an accidental blast killed 10 civilians and injured many others at an ammunition market in Kabul.

    The suicide bombing in Khost is the fourth one over the past two days in Afghanistan.

    On Tuesday, a suicide bombing killed three civilians and injured eight others in Spin Boldak district of the southern Kandahar province, while two other suicide blasts injured at least four persons in Laghkar Gah, capital of the southern Helmand province.

    Taliban commanders said 2,000 suicide bombers would launch a bloody spring offensive against foreign troops in this country.

    As it gets warmer, Afghanistan has witnessed many more suicide or roadside bombings and clashes than last winter.

    A roadside bombing killed nine policemen including a district police chief in the western Farah province on Monday.

    Due to rising Taliban-linked insurgency, over 400 persons have been killed in Afghanistan this year.