A Pakistani court ordered the arrest of former president Pervez Musharraf on Thursday in connection with charges relating to his showdown with the judiciary in 2007 when he was still in power, television channels and one of his aides said.

The former army chief returned to Pakistan last month after nearly four years of self-imposed exile to contest a May 11 general election, despite the possibility of arrest on various charges and death threats from the Pakistani Taliban.

Election officials had barred Musharraf from running for the National Assembly earlier this week, effectively derailing his attempts to regain a place in politics.

Although Musharraf's legal battles have provided an electrifying sideshow in the election race, he commands scant popular support and the outcome of the drama is unlikely to have much impact on the final results.

Former Prime Minister Nawaz Sharif, the man Musharraf ousted in a coup in 1999, is seen as the frontrunner to win the premiership.

"Islamabad High Court has cancelled Musharraf's bail and ordered his arrest in the judges' detention case today," Mohammad Amjad, secretary-general of Musharraf's All Pakistan Muslim League party, told Reuters.

Islamabad High Court ordered Musharraf be detained in connection with allegations that he committed treason when he sacked senior judges and declared emergency rule as he struggled to hold on to power. Critics said he acted unconstitutionally.

Police made no immediate move to enforce the arrest order and Musharraf left the court flanked by his personal bodyguards.

Various legal cases against Musharraf have been pending for several years but the proceedings have gathered pace since his return to the country, culminating in the arrest order.

Pakistan's military has ruled the nation for more than half of its 66-year history, through coups or from behind the scenes. It sets foreign and security policy even when civilian administrations are in power.

Pakistan's judiciary has, however, taken an increasingly assertive stance in recent years in confrontations with both the government and the army, and the move to issue an arrest order against a former army chief may rankle some in the military.

Some commentators believe it is unlikely Musharraf will be arrested for any significant period since the military would be unlikely to tolerate such a humiliating spectacle for a retired general.

"It won't make any difference even if he is arrested - I don't think the military establishment would support any move against him," said Mehdi Hasan, a newspaper columnist.

Musharraf's decision to return has mystified many Pakistanis, with commentators questioning whether he misjudged the degree of popular support he might be able to muster.

The former army chief also faces charges of failing to provide adequate security for former prime minister Benazir Bhutto before she was assassinated in late 2007.

Musharraf also faces accusations in connection with the death of a separatist leader in the southwestern province of Baluchistan. He denies any wrongdoing. - Reuters