A suicide bomber on a bicycle attacked a police checkpost in southeast Afghanistan on Saturday, killing at least two civilians and wounding five others, provincial authorities said. "Two civilians were killed and five others are wounded in an explosion outside police security checkpost in the city of Ghazni today afternoon," said Mohammad Hasan, security chief for police in Ghazni, about 150 kilometres (93 miles) from the capital Kabul. The suicide bomber was riding a bike when he detonated his explosives, Hasan told AFP. Head of Ghazni city hospital, Baz Mohammad Hemat, confirmed the death toll, adding that 13 civilians -- including women and children -- were wounded in the explosion. There was no claim of responsibility for the assault, but such attacks have in the past been carried out by Taliban insurgents who are leading an 11-year war against the US-backed government of Afghan President Hamid Karzai. Ghazni province has become a volatile one in recent years with the Taliban holding strong sway in southeastern Afghanistan. The assault comes a day after a suicide car bomber attacked a NATO convoy in Afghanistan's strategic Kapisa province, killing five civilians and wounding 15 others.