Senior police officers were among 13 people killed on Monday when a Taliban suicide bomber blew himself up targeting them during a protest rally outside Pakistan's Punjab assembly in Lahore that also wounded more than 71 others.
Inspector General Police Punjab Mushtaq Sukhera said that 13 people, including six security men, were killed in the suicide blast which had targetted police officials.
He said the suspected suicide bomber reached the police officials by foot and blew himself up.
Lahore Traffic Police chief Capt (R) Ahmed Mobeen and Senior Superintendent Police Zahid Gondal were among the dead.
Lahore police chief Amin Wains confirmed the death of Mobeen. He, however, did not confirm about other casualties.
Deputy Commissioner Lahore said that at least 73 people had been injured in the blast.
Punjab Health Minister Khawaja Salman Rafique said the condition of some 11 injured was critical.
The Jamat-ul-Ahrar faction of the outlawed Tehreek-i-Taliban Pakistan claimed responsibility for the attack.
The group had claimed responsibility for a blast on March 27 last year at Gulshan-e-Iqbal Park in Lahore that left 75 people dead, mostly Christians who were celebrating Easter.
The security forces have cordoned off the area and the inner cordon was taken over by Army personnel. Forensic teams were collecting evidence and had started investigations.
The blast was so powerful that it was heard several kilometers from the spot.
"The chemists were protesting against the controversial drug regulations the government has recently imposed. Several protesters were lying on the road before the rescuers shifted them," said Ishtiaq Ahmed, a representative of the Lahore Chemist Association.
DIG Mobeen had survived an attempt to his life during his posting in Balochistan.
A Lahore police officer said that apparently it was a suicide attack and the bomber targeted the police personnel present there.
"The target was not the protest demonstration but the police officers," he added.
The blast occurred minutes after Mobeen 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. Mobeen is seen in the footage negotiating with the protesters.
Prime Minister Nawaz Sharif condemned the blast and said that fight against militants would continue. He promised to avenge the lives lost in Monday's terror attack.
"We have fought this fight against the terrorists among us, and will continue to fight it until we liberate our people of this cancer, and avenge those who have laid down their lives for us," Sharif said in a statement.
Lahore is home town of Sharif and seat of his power as Punjab is the only province where his party rules without support of any other party.
Army Chief General Qamar Bajwa condemned the terrorist attack in Lahore, the army said in a statement.
Gen Bajwa instructed area Army commander and intelligence agencies to provide all necessary assistance to the civil administration in the evacuation of injured to hospitals and also to apprehend those responsible for this heinous act.
Punjab Law Minister Rana Sanullah said the agencies had issued a threat alert that terrorists might target Punjab Assembly building and Governor's House on the Mall Road.
"We have provided security to these venues. Had no demonstration taken place outside the PA building this incident might not have taken place," he said.
A notification issued by the National Counter Terrorism Authority on February 7 warned that an unidentified terrorist group was plotting a terror attack in Lahore.