Security officials inspect the site of a bomb blast.

At 3 two people were killed and 26 injured Thursday by a bomb blast in a busy shopping district of the Pakistani city of Lahore, police said.

"Initial investigations show that it was a time-controlled device on a motorbike which was the cause of the blast," Rana Arif, spokesman for Lahore police, told AFP.

Officials said a nine-year-old child was one of those killed.

pakistani Prime Minister Imran Khan expressed regret over the "loss of precious human lives", a spokesman for his office said.

On Twitter, a spokesman for the Baloch Nationalist Army said it was responsible.

"This attack targeted bank employees. A detailed statement will be issued soon," the tweet said.

Mineral-rich Balochistan, bordering Afghanistan and Iran, is the largest of pakistan's four provinces, but its roughly seven million inhabitants have long complained they do not receive a fair share of its gas and mineral wealth.

China is investing in the area under a $54-billion project known as the China-pakistan Economic Corridor (CPEC), upgrading infrastructure, power and transport links between its far-western Xinjiang region and pakistan's Gwadar port.

Baloch separatists previously claimed several attacks on CPEC projects, and thousands of pakistani security personnel are deployed in the region to counter the violence.