Two policemen were killed on Friday in an exchange of fire between a security guard and unidentified assailants near the Chinese Consulate in Karachi, police said.
Deputy Inspector General (DIG) South Javed Alam Odho confirmed the death of the two policemen, reports Dawn news.
An explosion, the nature of which has not been determined as yet, was also heard in the high-security Clifton area.
According to initial reports, heavy contingents of police and Pakistan Rangers have been deployed.
Governor Sindh Imran Ismail has taken notice of the incident and called for a report on the matter from the Sindh inspector general of police.
The governor has also contacted Sindh Chief Minister Murad Ali Shah.