Pakistani police say a bomb has exploded near a police checkpoint killing three police and a bystander and wounding 20 others near the eastern city of Lahore.

Haider Ashraf, Lahore police chief, says Wednesday that an initial investigation suggests the bomb was planted near the checkpoint close to a religious group's main congregation place in Raiwind near Lahore, the capital of Punjab province.

Ashraf said many of the wounded were police and three were hospitalized in critical condition. Other wounded included members of the Islamic preaching group known as Tablighi Jamaat.

The main country's Taliban group Tehrik-e-Taliban Pakistan claimed responsibility, saying it was a suicide attack.

Lahore and its surroundings have seen many bomb and suicide attacks in recent years.