At least six persons were killed and about 30 others injured when a bomb went off inside a mosque in the restive city of Peshawar in northwest Pakistan on Saturday, witnesses and officials said.

The blast occurred in the busy Meena Bazar area of Peshawar at around 1 p.m.

About 30 worshippers were in the mosque while a large number of people, including women and children, were in the market at the time of the attack.

Officials at the Lady Reading Hospital said they had received six bodies and about 30 injured. They described the condition of three injured persons as serious.

No group claimed responsibility for the attack though such bombings are usually blamed on the banned Tehrik-e-Taliban Pakistan.

Witnesses said the bomb went off as several worshippers were offering prayers or performing ablutions.

Footage on television showed the blast created a crater inside the mosque.

Some parts of the mosque collapsed while the walls were pitted with shrapnel.

Rescue teams faced problems in gaining access to the site through narrow alleys.

Meena Bazar and other nearby markets were shut down after the blast.

In recent weeks, Peshawar and other parts of the northwestern Khyber-Pakhtunkhwa province have witnessed a string of attacks blamed on the Taliban.

Provincial Chief Minister Ameer Haider Khan Hoti had a narrow escape recently when a suicide bomber blew himself near his motorcade. The attacks have raised questions about security for polls expected to be held by May.