Five policemen were killed and two others injured when unknown gunmen launched an attack late Saturday night at a police training station in Pakistan's southern port city of Karachi, reported local media Geo News.

According to the report, the incident took place at about 11:30 pm (local time) in the Baldia town area of Karachi. The gunmen fled the scene after the attack, the report quoted police sources as saying, adding that no group has claimed the responsibility for the attack.

In another development, Geo News reported an Islamic scholar was gunned down along with his second son in New Karachi area on Saturday night. They were shot dead by unknown gunmen riding on motorbikes. The slain scholar, named Maulana Muhammad Ahmed Madni, is administrator of Madresah Talim Al-Quran and he is a brother of a late leader of a local banned outfit.

Prior to this, a blast that occurred Saturday afternoon in the city killed at least two persons and injured three others.

Killing and bloodshedding is almost a routine phenomenon in Karachi. But local watchers said Saturday's three incidents that had claimed almost ten lives might indicate a return of new violence to the city.