Police in Pakistan say three members of the country's security forces have been killed in separate attacks in the southern city of Karachi.

Senior police officer Amir Farooqi says in the first attack Wednesday, assailants threw a grenade at a vehicle carrying paramilitary Rangers in the Nazimabad neighborhood of Karachi, killing one of them. He says minutes later, a roadside bomb wounded three security personnel in the same area.

Farooqi says about an hour later, a suicide bomber blew himself up outside the headquarters of the paramilitary Rangers, killing one Ranger and a private guard.

Karachi is the capital of southern Sindh province. It has been the scene of scores of such attacks against security personnel in recent years.