At least six people have reportedly been injured in a blast that ripped through a section of the Philippine house of representatives.
"There is a bomb that exploded in the south wing of the Batasan complex," Jose De Venecia, the house speaker, told local radio.
He also said it was caused by a bomb.
Local radio said a "huge explosion" took place in the south lobby of the chamber just after 8pm(1200 GMT) on Tuesday, following the end of a session of congress.
The blast sent bits of concrete flying across the parking lot.
"It looks like there were a number of people injured," said Joel Villanueva, a congressman.
At least two members of the parliament are thought to be among the injured.
Al Jazeera's Marga Ortigas, reporting from the capital Manila, said the police have set up checkpoints in many surrounding areas following the blast.
Lorenzo Tanada, another congressman, told Al Jazeera that the blast could be heard as far as 10km away.
"It was such a loud explosion," he said.
A blast last month tore through a shopping mall in Manila's financial district, leaving 11 people dead and injuring over 100.
Police initially thought a bomb was to blame, but later said the explosion was an industrial accident.