New Delhi, Mar 11: Union External Affairs Minister Pranab Mukherjee on Tuesday expressed concern the two bomb blasts that rocked Lahore in which 25 people were killed.

"It is a matter of concern and we are really worried over and I do hope as and when the new government is established they would be in a position to restore normalcy and the fight against terrorism will be further strengthened," Mukherjee told reporters on the sidelines of function.

At least 25 people, including 13 Federal Investigation Agency (FIA) officials were killed in the blasts and 200 others injured.

The two bombs ripped through a federal police headquarters and an advertising agency in Lahore on Tuesday morning. The blasts were the latest in a wave of violence across Pakistan that has left more than 600 people dead this year and posed a serious challenge to an incoming coalition government that won elections on February 18.

The deadliest blast demolished much of the seven-storied federal police headquarters, which has now been declared too dangerous for occupation.

Rescue workers in orange jackets continue to frantically claw through the debris at the site of the blast in an attempt to retrieve survivors, if any.

The second near-simultaneous blast was also caused by a suicide car bomb and hit an advertising agency in an upscale neighbourhood of the city, killing another four people, including two children, police said.

The explosions came a week after two suicide bombers blew themselves up at the Naval War College in Lahore, killing at least five people and wounding 19, officials said.

Pakistan has been rocked by six major blasts since parliamentary polls on February 18, which were won by the parties of slain ex-premier Benazir Bhutto and former Prime Minister Nawaz Sharif.

Pakistan has been combating an Islamist insurgency led by Al-Qaeda and Taliban fighters since Musharraf joined the US-led "war on terror" in 2001, but the violence has soared since the start of 2007.

Many of the attacks have targeted the armed forces, police and security forces. The army's top medical officer, Lieutenant General Mushtaq Baig, was killed in a suicide attack in the garrison city of Rawalpindi on February 25. (ANI)