(KUNA) -- Four senior police officers and a civilian were killed and more than five others were wounded, two of them critically, in a drive-by shooting Thursday in the commercial city of Karachi, said police. Police officer Amanullah Niazi told KUNA in a telephone call that two armed motorcyclists intercepted a police and a government vehicle in Saddar area of the city and sprayed bullets at them.He said the firing killed four policemen including Deputy Superintendent Police (DSP), Assistant Superintendent Inspector (ASI) and two constables, as well as a civilian. He added that more than five people were also wounded and two of them were said to be critical condition. He termed the incident as being an act of terrorism and said police had launched investigations.