Three assailants strapped with explosives have attacked the Chinese consulate in Pakistan’s southern city of Karachi, leaving two policemen dead.

The city’s police chief said the attackers were killed before entering the building early Friday.

An exchange of fire erupted between the guards and the gunmen, which also resulted in the “killing two of our constables and critically wounding another,” said senior local police official Javaid Alam Odho.

The separatist Pakistani group, the Balochistan Liberation Army (BLA), claimed the attack. “They stormed the Chinese embassy in Karachi. China is exploiting our resources,” the group’s spokesman Jiand Baloch said.

Pakistani Foreign Ministry said in a statement that all 21 Chinese staff inside the consulate are safe.