Authorities have traced the whereabouts of the suicide bomber who killed at least 15 people outside Punjab Assembly in Lahore, said the provincial chief minister, after police said they had arrested the alleged facilitator of Monday’s bombing.

Chief Minister Shahbaz Sharif said the bomber hailed from Afghanistan. He added that the alleged facilitator belong to Bajaur Agency, a restive region in the volatile Federally Administered Tribal Areas (Fata).

The Counter-Terrorism Department said it had arrested the alleged facilitator from a cloth market in Lahore. The suspect was taken to an undisclosed location for interrogation.

The explosion had killed at least 15 people and wounded 83 others on Monday.

Mushtaq Sukhera, inspector general of police in Punjab, said five police officers were among the dead when an explosion rocked a protest organised 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 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.