KABUL, July 31 (Xinhua) -- At least eight people were killed and 40 others wounded as a roadside bomb blast struck a passenger bus in Afghanistan's western province of Farah on Tuesday, local government said.

The explosion occurred at around 04:30 a.m. local time along a main road in Lakhshak locality of Bala Buluk district after the bus touched off an improvised explosive device (IED), the provincial government said in a statement.

Among those killed was a woman and several other women and children were among the injured. The bus was carrying passengers from western Herat province to national capital of Kabul.

The province has been the scene of heavy clashes between security forces and Taliban militants over the past months.

The statement blamed Taliban for planting the IED.

The militants have been using IEDs to make roadside bombs and landmines for targeting security forces, but the lethal home-made weapons also inflict casualties on civilians.

More than 1,690 civilians were killed and over 3,430 others injured in conflict-related incidents in the first half of the year in the war-torn country, according to figures released by the United Nations mission in the country.