KABUL, AFGHANISTAN - One U.S. soldier and an Afghan were killed when a suicide bomber tried to attack a base in southeast Afghanistan on Saturday, officials said, two days after a major operation against the Taliban was launched in the south.

The bomber drove a truck toward the base, operated by U.S.-led foreign forces and Afghan troops, in the Zirok district of southeastern Paktika province, said Hamidullah Zwak, a spokesman for the provincial governor.

He ignored warnings to stop and was shot dead before he reached the base, Zwak said. The explosives he was carrying detonated during the shooting, he said, killing the soldiers.

A spokeswoman for U.S. forces in Afghanistan said she was aware of an incident in Paktika but did not know any details.

A spokesman for the International Security Assistance Force in Afghanistan said there had been an attempt to attack a combat operating post in Zirok and that there were casualties, but he had no other details yet.

Thousands of U.S. Marines launched a major offensive in southern Helmand province, a Taliban stronghold and major opium poppy producing area, on Thursday, the first big operation of U.S. President Barack Obama's new regional strategy to defeat the Taliban and stabilize Afghanistan.

The Marines and other forces have so far met little resistance and there have been no reports of big reprisal attacks by the Taliban or its allies since Operation Khanjar, or Strike of the Sword, was launched.

Taliban spokesman Zabiullah Mujahid said several Afghan and foreign soldiers were killed in Saturday's attack in Zirok and said the truck had been packed with explosives. There was no independent verification of his claim.

The Marines launched their new operation with violence in the Taliban-led insurgency at its worst since the Islamist group was ousted from government in late 2001.

The new operation was launched after years of stalemate in the south, which provides most of the poppy crop that funds the insurgency, with the hope that it would turn the tide of a war some in Washington say they are not winning.

The new strategy is also meant to help improve security for August 20 presidential elections in Afghanistan. --REUTERS