Islamabad, Feb 14 (IANS): The toll in the terrorist attack on a Shia mosque in Peshawar city in northwestern Pakistan rose to 21 after an injured person died of his wounds Saturday, officials said.

Mushtaq Ghani, information minister of Khyber Pakhtunkhwa province, confirmed the toll and called for the deployment of Frontier Corps personnel, Dawn reported.

He said the Imambargah was very close to tribal areas, which allows easy access to terrorists.

Meanwhile, banned militant outfit Jundullah, a splinter group of the Tehreek-e-Taliban Pakistan (TTP), claimed responsibility for the Friday terrorist attack through an email statement later in the evening.

It claimed that the attack was carried out to avenge the hanging in December last year of a militant known as Doctor Usman.

"This was a series of taking blood for blood, which would continue. The government should expect more and even harder responses," the statement said.

The proscribed group also posted a photograph of what it claims are the attackers involved in Friday's carnage.

Eyewitnesses and sources said that the attack took place when people were offering prayers in the mosque.