Pakistanis Tuesday mourned the victims of a Taliban-claimed suicide bomb in Lahore, as the death toll rose to 15 and the city's residents railed at the government for failing to protect them.

The chief minister of Punjab state Shahbaz Sharif declared a day of mourning after Monday's blast on Lahore's Mall Road, one of the city's main arteries, at rush hour during a busy protest.

At least 15 people were killed, emergency official Ahmad Raza told AFP, including six police officers, while up to 87 were injured.

The toll could have been much higher, Raza said, but for two vehicles -- a TV news van and a minivan belonging to the protesters -- which absorbed much of the impact of the blast.

The Pakistani Taliban faction Jamaat-ul-Ahrar claimed responsibility for the assault, which came three days after it announced it would carry out a series of attacks on government installations around the country.

A spokesman for the group warned in a statement that Monday's bomb was "just the start".

The attack underscored the challenges faced by Pakistan in its push to stamp out militancy, even as security dramatically improved in 2015 and 2016.

Local groups like the umbrella Tehreek-i-Taliban Pakistan (TTP) retain the ability to carry out spectacular attacks, despite a military-led crackdown on extremism.

Lahore residents vented their fury at the militants and the government at the blast site early Tuesday.

"They (the militants) have no link with Islam nor do they believe in any religion, the only thing they know is killing people, this is utterly an act of terrorism," Tariq Saleem told AFP.

Nadeem Akhter called on the government to do more to bring the situation under control. "Our children and people are being killed in these attacks," he said.  

Both British High Commissioner to Pakistan Thomas Drew and US ambassador David Hale branded the attack "cowardly" in separate statements, expressing support for the victims.

Lahore, the country's cultural capital, suffered one of Pakistan's deadliest attacks during 2016 -- a Jamaat-ul-Ahrar suicide bomb in a park last Easter that killed more than 70 including many children.

But such incidents have been rare in the city in recent years.

Shortly after Monday's attack two members of a bomb disposal team were killed in Quetta, the capital of restive Balochistan province, while trying to defuse a device.

It was not clear if the Quetta bomb was linked to the Lahore attack. 

source: AFP