Altogether 20 civilians were killed on Thursday afternoon in a mine explosion in southwestern Afghan province, Nimroz, Afghan police officer told Xinhua.

The explosion broke out when a bus ran over a landmine on Thursday afternoon in Khash Rod District, in the north of Nimroz Province with Zaranj as its provincial capital, some 790 km southwest of Afghan capital Kabul.

"The ill-fated passenger bus hit a mine in Khash Rod District in the afternoon, leaving 20 dead and the driver injured," Mohammed Musa Rasuli, deputy police chief of Nimroz Provice told Xinhua reporter on Friday night.

"It is Taliban who planted the landmine," the deputy police chief said. Afghan Taliban are frequently engaged in IED ( Improvised Explosive Device) attack, always in the forms of suicide bombing and roadside bombing.

However, Taliban are not availble to make any comment over the incident so far.

The incident follows another roadside bombing in Marja district in southern Afghan province Helmand on Thursday morning in which six civilians were killed. Helmond provincial government later in a statement blamed the enemies of Afghanistan, a term used referring for Taliban insurgents for planting the bomb on the road and responsible for the attack in the province, some 555 km south of capital of Kabul.

The Taliban-led insurgency has been rampant since the militant group announced to launch spring offensive from May 1 against Afghan and NATO-led troops stationed in Afghanistan.

A total of 368 civilians were killed in conflicts and Taliban- led insurgency in May this year, the deadliest month for Afghan civilians since 2007, the United Nations Assistance Mission in Afghanistan (UNAMA) said in a statement earlier in June.