KABUL (Reuters) – Two U.S. soldiers were killed when their base in southeast Afghanistan came under attack on Saturday, the U.S. military said, two days after a major operation against the Taliban was launched in the south.

The attack included an attempted suicide truck bombing of the base in the Zirok district of southeastern Paktika province, local officials said. As many as 30 Taliban insurgents might have been killed when troops called in air strikes, they said.
It came after 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, began in Helmand.
Another seven U.S. soldiers and two Afghan troops were wounded in Saturday's attack on the combat outpost near Zirok, Lieutenant Commander Christine Sidenstricker said.
""It was a complex attack that started with small-arms and indirect fire on the post, then an improvised explosive device went off,"" Sidenstricker said.
""Air strikes were called in some time after,"" she said.
The international coalition in Afghanistan said in a later media statement that multiple rocket and mortar rounds had been fired at the outpost, one of which contained white phosphorus.
Afghanistan's Taliban have denied using the chemical, which bursts into flame on contact with the air and can cause horrific burns. A coalition spokesman said about 70 incidents of insurgents using or possessing white phosphorus had been documented since April.
Most commonly used on battlefields as a smokescreen or for illumination, its use to deliberately target people is illegal.
An 8-year-old girl was badly burned by white phosphorus in west Afghanistan in May, with the U.S. military and the Taliban accusing each other of firing the round containing the chemical.