Islamabad, March 16 (IANS): Pakistan Prime Minister Nawaz Sharif has strongly condemned the bomb blasts at two churches in Lahore city that killed at least 15 people and injured over 70, a media report said on Monday.

Two powerful explosions on Sunday rocked the Catholic Church and Christ Church in the city's Youhanabad area, home to the country's biggest Christian population.

Jamatul Ahrar, an offshoot of the Pakistan Tehreek-e-Taliban (TTP), claimed responsibility for the deadly attacks which took place as large crowds were in the area to attend Sunday prayers.

"Our Christian community has rendered invaluable services to the motherland particularly in the social sector and we consider them as our honour and pride," The Daily Times reported, citing Sharif as saying.

He extended his condolences to the bereaved families who lost their dear ones in the incident and said that "the government would work with them to find answers to their questions".

Violent protests erupted in Lahore soon after the blasts, the Daily said, adding that a 4,000-strong Christian mob armed with clubs smashed vehicles. Television footage showed dozens of stick-wielding men ransacking the city's metro bus terminal. Protestors also clashed with the police.

In Karachi, hundreds of Christians took to the streets and blocked roads. There were also demonstrations in Peshawar city in the country's north-west, in the city of Multan and in Quetta in the south-west

The prime minister observed that the emotions of anger and grief shown by the Christian community in the aftermath of this tragic incident strengthened the government's resolve to counter the menace of terrorism.

He asked all the provincial governments to beef up security and take all possible measures to safeguard life and property of the people.

He also sought reports on the incident and directed the authorities concerned for provision of best medical facilities to the injured.