A damaged bus is seen at a blast site in Attock, Punjab Province, Pakistan, on May 3, 2018. At least three people were killed and 13 others injured when a suicide bomber blew himself up near a bus in Pakistan's Punjab province on Thursday, local Urdu TV channels reported. (Xinhua)

ISLAMABAD, May 3 (Xinhua) -- At least three people were killed and 13 others injured when a suicide bomber blew himself up near a bus in Pakistan's Punjab province on Thursday, local Urdu TV channels reported.

According to the reports, the suicide attacker targeted a bus carrying employees of the Pakistan Atomic Energy Commission (PAEC) on Basal road near Dhok Gama area in Attock, a city in the province.

Police officials confirmed that, an employee of the PAEC and a passer-by were among the three killed in the attack whereas all the injured were employees of the PAEC.

The bus driver and a passer-by tried to overpower the attacker who blew himself up after firing shots at the bus, killing both of them on the spot, said District Emergency Officer Ashfaq, adding that the bus was completely destroyed by the powerful blast.

Security forces and rescue teams rushed to the site and shifted the injured to nearby hospitals in the city.

Security forces have condoned off the area and kicked off a search operation.

No group or individual has claimed the responsibility of the attack yet.