A suicide bomber on a motorized rickshaw blew himself up in a crowded marketplace in southern Afghanistan on Monday, killing 28 people in one of the deadliest bombings since the fall of the Taliban.

The attacker was apparently targeting a police commander when he detonated his bomb in the town of Gereshk in Helmand province, the world's largest poppy-growing region.

Gereshk district chief Abdul Manaf Khan said about 28 people were killed, a total that included 13 police and about 15 civilians.

The provincial chief of public health, Enayatullah Ghafari, said the hospital recorded 26 deaths and 60 wounded, though he said some of the dead probably weren't brought to the hospital and the death toll was likely higher.

The blast came just before evening prayers in the Muslim country, near a taxi stand, Khan said.

Gen. Mohammad Zahir Azimi, a Defence Ministry spokesman, said a local police commander who survived the attack appeared to have been the target. A Taliban spokesman couldn't immediately be reached for comment.

Taliban militants have set off a record number of suicide blasts this year — more than 100 through the end of August — but few as deadly as the Helmand attack. The Taliban typically target international and Afghan military and police forces.

With 28 dead so far, Monday's attack appears to be the second-deadliest bombing in Afghanistan this year and the third-deadliest since the fall of the Taliban in late 2001.

In June, 35 people were killed in a bomb attack on a police bus in Kabul, while in September 2002, 30 people were killed and 167 wounded in a Kabul car bombing.

Afghanistan has seen a spike in violence this year, especially in the south. More than 4,200 people, mostly militants, have died in insurgency-related violence in 2007, according to an Associated Press count based on figures from Afghan and Western officials.