Kabul, Aug 18 (DPA) A suicide bomber rammed his explosives-filled car into an international military convoy Tuesday in Kabul, killing seven civilians, two Afghan UN staffers and one NATO soldier.

The Taliban claimed responsibility for the attack, which also left wounded 53 Afghan civilians, and two NATO soldiers, as another bomber Tuesday attacked an army checkpoint in the southern province of Uruzgan, killing five people.

The bombings came two days before Afghans go to the polls to directly elect a president for only the second time in their history and raised concerns in the war-weary Central Asian country that the elections would be overshadowed by violence.

President Hamid Karzai, who is running for re-election Thursday, condemned Tuesday's attacks, saying: 'The enemies of Afghanistan are worried about massive participation of people in the elections, and by carrying out these terrorist attacks, they try to prevent them from going to voting centres.'

'But despite enemies' efforts, the Afghan people with their understanding of the importance of elections, would go to polling stations,' Karzai said in a statement issued by his office.

The NATO-led International Security Assistance Force confirmed that the Kabul attack was against one of its convoys.

'Updated reports indicate that those killed were one ISAF service member, seven Afghan civilians and two Afghan civilian employees of the United Nations Assistance Mission in Afghanistan,' the ISAF said in a statement.

'The reports that we have from all our hospitals in Kabul say seven people were killed and 52 others, including children, were wounded,' Farid Rahid, spokesman for Afghan Public Health Ministry.

Zabiullah Mujahid, a spokesman for Taliban militants, said the attack was against US military forces.