KANDAHAR, Afghanistan - A suicide car bomber killed at least two civilians in an attack outside a major international military base on Monday in Afghanistan's southern Kandahar province, a Taliban stronghold, army officials said.

The bomber apparently targeted a group of Afghan soldiers and truck drivers providing supplies for foreign troops at the sprawling Kandahar air field south of Kandahar city.

"It was a suicide car attack which killed two truck drivers and wounded 10 more of them, along with two (Afghan) army soldiers," said General Sher Mohammad Zazai in Kandahar.

Another army officer, who requested anonymity, said four Afghan soldiers were also killed. No other details were immediately available.

The were no casualties among the foreign troops, the two officers said.

Attacks by insurgents have reached their highest level since the Taliban were ousted in 2001, U.S. military commanders say.

In an attempt to regain the initiative, thousands of U.S. Marines last week launched a major new offensive in neighboring Helmand province, another Taliban stronghold and the center of the opium poppy trade that funds the insurgency.

The Helmand offensive is the first major operation under U.S. President Barack Obama's new regional strategy to defeat the Taliban and its allies and stabilize Afghanistan.

Suicide attacks and roadside bomb blasts are the most common weapons used by the Taliban in their campaign to drive out almost 90,000 U.S. and NATO-led troops and to destabilize President Hamid Karzai's Western-backed government.

Afghanistan voters go to the polls on August 20 in the country's second presidential election.

U.S. troops, with the help of armed Afghan groups, overthrew the Taliban in 2001 after the hardline Islamists refused to hand over al Qaeda leaders wanted by Washington over the September 11 attacks on the United States that year.

(Reporting by Ismail Sameem; Writing by Sayed Salahuddin; Editing by Paul Tait)