A suicide attack outside a US military base in eastern Afghanistan killed nine Afghan civilians Monday, while NATO forces earlier killed four civilians with rockets in the south, officials said, dpa reported.
In other incidents, a British soldier was killed in the south, and several militants were killed in separate clashes in southern and northern Afghanistan, the military said.
A suicide bomber had detonated his explosives-laden vehicle outside a compound in the eastern Khost province, killing nine labourers who were standing in line for a security check to enter the US base, provincial Governor Arsala Jamal told Deutsche Presse-Agentur dpa.
Jamal said 13 other labourers had been wounded in the attack, and police had shot and killed two would-be suicide bombers riding in another vehicle packed with explosives near the base.
"The explosion did not penetrate the base's perimeter," a US military statement said.
US forces assisted in taking the wounded to the base hospital, it said, without saying whether there were any US casualties.
The suicide attack took place hours before President Hamid Karzai and other senior government officials celebrated the 89th anniversary of Afghan independence from Britain.
Karzai congratulated his countrymen on the occasion of Independence Day in a televised address to the nation.
Most in the capital stayed home Monday, while 7,000 additional security personnel patrolled Kabul city. The forces also closed several roads leading into the centre.
The unprecedented security measures were taken following warnings from top commanders of the US-led coalition and NATO forces of possible attacks during the celebrations, citing "credible intelligence reports."
Karzai condemned the attack and said that the country would remain free and independent despite the acts of "terrorists."
"The enemies, by killing civilians on our independence day, showed that they are opposed to Afghanistan's freedom and cannot see the happiness of Afghan people on their independence day," Karzai said in a statement issued by the presidential palace.
In the southern province of Helmand, four civilians were killed and three were wounded Saturday during a NATO attack on insurgents positioning themselves to attack a military convoy in the Sangin district, the alliance said in a statement.
"The patrol identified insurgents with weapons on the roof of the compound preparing to attack, and in order to protect themselves launched three rockets, all of which hit the target," the statement said.
"Unbeknown to the patrol, the civilians were inside the compound at the time," it said, adding that the dead and wounded civilians were all women and children.
Meanwhile, a British soldier was killed in an insurgent attack in southern Afghanistan on Monday, NATO said in a statement, without saying where the attack had taken place.
Around 8,000 British troops are stationed in southern Helmand province as part of the 50,000-strong NATO-led mission in Afghanistan.
Several militants were also killed Sunday when a group of insurgents attacked US-led forces during a search operation in the Tag Aab district of north-eastern Kapisa province, a US military statement said.
The troops responded to the insurgents' attack with small-arms fire and airstrikes and recovered weapons and ammunition, it said.
Taliban-led attacks have been on the rise in southern and eastern regions of the country.
Afghan and international forces said over the weekend that their forces had killed more than 100 insurgents in recent combat operations, while 10 policemen and five private security guards were also killed over the weekend in Taliban attacks.
About 3,000 people, including at least 1,000 civilians, have been killed in violence so far this year, according to figures provided by Afghan and foreign military sources.