Three top police officers were among 16 people killed today when a suicide bomber blew himself up targeting them during a protest rally outside Pakistan's Punjab assembly in Lahore that also left 69 others injured. Lahore Traffic Police chief, Senior Superintendent Police and DSP were killed in the blast.<br/><br/>At least 16 people were killed in the powerful blast that ripped through the protest rally, police officials said.<br/><br/>Punjab Health Minister Khawaja Salman Rafique said more than 60 people suffered injuries. The condition of some 11 injured is stated to be critical.<br/><br/>A police officer in Lahore told PTI that apparently it was a suicide attack and the bomber targeted the police personnel present there. <br/><br/>The blast occurred minutes after Police officials arrived at the scene to negotiate with the chemists and pharmaceutical manufacturers who had been protesting outside the assembly. A TV footage shows that a motorcyclist dragging his bike close to police officers and blew himself up. <br/><br/>The chemists were protesting against the controversial<br/>drug regulations the government has recently imposed. <br/><br/>The Jamat-ul-Ahrar faction of the banned Tehreek-i-Taliban Pakistan has claimed responsibility for the attack.