ISLAMABAD: Police and security officals have arrested a gunman in Islamabad on late Thursday night who had been demanding the implementation of an Islamic system in Pakistan.

The gunman is now in police custody. Sources suggest that the gunman was injured after one bullet hit him in the stomach and another bullet hit his leg.

He has been taken to Pims hospital where he is undergoing an operation to treat his wounds. Hospital sources said that he is in a serious condition.

The Interior Minister Chaudhry Nisar had given the order that the man should be taken alive.

Pakistan Peoples Party (PPP) leader Zamurd Khan was instrumental in helping to capture the gunman when he jumped at him and tried to take away his weapon.

Earlier on the armed man opened fire in the heavily policed heart of Islamabad after slipping past the capital's many checkpoints.

Security has been tight in Islamabad after police received an alert about possible attacks by militants operating from the tribal areas on Pakistan's lawless border with Afghanistan.

As night fell, the unidentified man drove a black vehicle into the tightly guarded centre of Islamabad, stopped within a stone's throw from the president's official residence and opened fire in the air.

The gunman had a Kalashnikov in his possession along with a submachine gun. A woman and two children were also in the car with him.

“I am against vulgarity and immorality. My associates have taken up positions in the whole of Pakistan,” he told a local TV channel.

Hundreds of onlookers gathered in the central Jinnah Avenue as night fell and periodic gunshots rang out in the air.

Checkpoints and police armed with assault rifles dot many major access points in Islamabad, where attacks have become rare in recent years.

Security has been tightened further in past weeks, particularly in the city centre where most government buildings and diplomatic missions are located.

Although he appeared to act on his own and seemed confused in his demands, it was unclear how the man, armed with at least two automatic rifles, managed to paralyse the city centre and cause a standoff with police including anti-terrorist units.