Musharraf was not harmed in the explosion and there was no immediate claim of responsibility for the bombing.

The Pakistani general had survived multiple assassination attempts while he was in office. When he returned to the country last year, the Pakistani Taliban vowed to kill him.

In the latest attack, Musharraf was traveling from the military hospital in Rawalpindi where he's been treated since January to his house in the capital of Islamabad when the blast went off early Thursday, said police official Mohammed Hayat.

Musharraf's convoy had crossed a bridge entering the capital when the bomb exploded shortly after, Hayat said. He said the blast was caused by 2 kilograms (4.4 pounds) of explosives, adding that it was not clear whether it was a remote control or time device.

Hayat said Musharraf appeared to be the target of the blast but it was not immediately clear how far his vehicle was from the explosion.

Musharraf's spokeswoman, Aasia Ishaq, said the retired general was already at home when the blast went off and that he was fine. An aide to Musharraf who did not want to be identified because he was not authorized to speak to the media, said the convoy had left the hospital about 20 minutes earlier than planned.

Ishaq said it was up to the authorities to make sure nothing happens to him.

"All extremist and terrorist forces want to kill Musharraf," said the spokeswoman. "If anything happens to Musharraf, the government will be responsible."

The blast ripped up a small section, about one-yard wide, of the brick sidewalk. Police initially cordoned off the area to gather evidence but later removed the tape and traffic passed freely.

Musharraf, 70, took power in a 1999 coup and served until 2008, when he was forced to step down as his popularity plummeted. He later went into self-imposed exile. Musharraf returned in March of last year to run in the elections — only to be disqualified and immediately face a number of legal challenges related to his time in office.

The most serious is a high treason case brought against him by the government that could result in the death penalty if he's convicted. The case stems from his decision to suspend the constitution on Nov. 3, 2007, and detain a number of judges.

Musharraf was formally charged in the case on Monday. It was only his second appearance in the court proceedings which started in December. He missed multiple appearances due to security concerns and others after going to the hospital in early January after complaining of chest pains.

His legal team has pushed for him to be allowed to leave the country to seek medical treatment and to visit his ailing mother but the government and courts have so far not approved their requests.