An explosion near the Punjab provincial assembly in the Pakistani city of Lahore killed at least 13 people and wounded 83 others on Monday, a senior police official said, APA reports quoting Reuters.
Mushtaq Sukhera, inspector general of police in Punjab province, said five police officers were among the dead when an explosion rocked a protest organized by Pakistan's chemists and pharmaceuticals manufacturers.
"It was a suicide attack. The bomber exploded himself when successful negotiations were underway between police officials and the protesters," Sukhera told reporters.
A spokesman for Jamaat-ur-Ahrar, a faction of the Pakistani Taliban, called Reuters and claimed responsibility.
The militant group also warned the Lahore attack was the start of a new campaign against government departments. "You are on our target across the country," it added in a statement.
Jamaat-ur-Ahrar had also claimed responsibility for an Easter Day bombing in Lahore last year that killed more than 70 people in a public park.
Security in Pakistan has vastly improved in recent years but Islamist groups such as the Pakistani Taliban and Islamic State still pose a threat and have carried out mass attacks.
Prime Minister Nawaz Sharif said the attacks will not weaken Pakistan's resolve in fight against militancy.
"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," he said in a statement.
The latest blast may jeopardize plans by Pakistan, a cricket-obsessed nation, to host the final of its domestic Twenty20 tournament on home soil in Lahore in March.
For years, Pakistan's international test cricket matches have been played abroad and the current Twenty20 tournament is being played in United Arab Emirates due to security fears.
At least 11 people -- including two senior police officers -- were killed and over 70 injured when a suicide bomber struck in Pakistan’s northeastern Lahore city on Monday evening, officials and local media reported, APA reports quoting Anadolu Agency.
The blast occurred during a busy protest against pharmaceutical companies outside the state assembly of Punjab, of which Lahore is the capital.
Lahore’s security forces told reporters a city police chief, Zahid Gondal, was among the dead.
The deputy commissioner Lahore Sameer Ahmed Syed told reporters 11 people had died and 73 had been injured.
Among the injured were two journalists and several policemen.
Punjab law minister Rana Sanaullah told reporters the blast seemed to be the act of a suicide bomber.
Later, Jamat ul Ahrar (JUA) -- a splinter faction of Tehrik-e-Taliban Pakistan (TTP), a consortium of Pakistani Taliban groups -- claimed the attack in a statement, saying the "suicide blast" was a joint act by the JUA, the TTP, and the Waziristan Mujahiddin, a little-known group.
Giant plumes of thick smoke and flames billowed upward as several vehicles parked across the road caught fire soon after the blast.
Blood-soaked caps, shoes, pieces of clothes and human flesh were strewn across the tree-lined site of the blast.
Local TV channels aired footage showing a man approaching some media vans parked near the protesters before the blast.
TV footage from the scene also showed policemen and protesters carrying injured people on their shoulders, running towards ambulances and private vehicles impeded by congested traffic.
The army has been called in to join the rescue operation.
Pakistani police say a large bomb has struck a protest rally in the eastern city of Lahore, killing at least seven people and wounding 40, Associated Press reported.
Local police official says Monday's blast occurred when a man on a motorcycle rammed into the crowd of hundreds of pharmacists, who were protesting new amendments to a law governing drug sales.