Attack, explosion near court in Pakistan; casualties feared

People light candles and oil lamps in tribute to the victims of Thursday's suicide attack at Lal Shahbaz Qalander shrine in Sehwanshrine, in Karachi, Pakistan, Saturday, Feb. 18, 2017. Pakistani authorities shut down a second key border crossing into Afghanistan, halting trade supplies to the neighboring landlocked country and increasing tensions between the two nations in the wake of a bloody suicide bombing at the beloved shrine in Pakistan, officials said Saturday. (AP Photo/Fareed Khan) (The Associated Press)

A Pakistani volunteer carries an injured child to a hospital in Peshawar, Pakistan, Tuesday, Feb. 21, 2017. Police say three suicide bombers have attacked a courthouse in northwestern Pakistan. Charsadda police chief says one of the bombers detonated his suicide vest at the court's main gate while police shot and killed the two other assailants. (AP Photo/Mohammad Sajjad) (The Associated Press)

Pakistani volunteers rush an injured person to an emergency ward at a hospital in Peshawar, Pakistan, Tuesday, Feb. 21, 2017. Police say three suicide bombers have attacked a courthouse in northwestern Pakistan. Charsadda police chief says one of the bombers detonated his suicide vest at the court's main gate while police shot and killed the two other assailants. (AP Photo/Mohammad Sajjad) (The Associated Press)

Pakistani officials say an attack, followed by an explosion has hit outside a courthouse in the country's northwest.

Police official Sajjad Khan says one or two gunmen tried to enter the court building but were prevented by the police, which was followed by a big blast on Tuesday. It wasn't immediately clear what caused the explosion.

Senior local government official Tahir Zafar says there are fears of casualties in the incident, which took place in the town of in Tangi in the Charsadda district.

Pakistan has been hit by a series of brazen suicide bombings last week that were claimed by various Islamic militant groups and that killed over 100 people.