Lieutenant Colonel Abbas Mohammed al-Bayati said the bomb went off as the convoy entered the town of Tuz Khurmatu, 70 km (40 miles) south of the northern oil city of Kirkuk late on Friday. A presidential spokesman declined comment.

As Reuters reports police said an adviser to Talabani was among the wounded, but the extent of his injuries was not known. The convoy had been heading to Baghdad from Kurdistan when it was attacked. Talabani is a Kurd.

Sunni Arab rebels are fighting to overthrow the Shi'ite Islamist- and Kurdish-led government.

Most senior Iraqi officials travel by air as many of Iraq's roads, particularly the main routes leading north out of Baghdad, are too dangerous. The motorcades of Iraqi officials have come under frequent attack.

Sunni Arab rebels were angered by the results of last month's parliamentary elections which confirmed the dominance of the ruling Shi'ite Islamist Alliance, accusing the bloc of poll fraud.

Within minutes of the election results being released on Friday, rebels launched mortar attacks on two U.S. bases in the insurgent stronghold of Ramadi, causing minor injuries among U.S. soldiers.

The government on Thursday imposed a 48-hour lockdown on three predominantly Sunni Arab provinces and sealed off Baghdad to guard against insurgent attacks.

The U.S. military had warned they expected a surge in violence when the poll results were released.