Coalition forces detained four men after several rocket-propelled grenades were fired at a U.S. special operations base in eastern Afghanistan, a U.S. military spokesman said Saturday.

The men were detained Friday night near Asadabad in eastern Kunar province, said Col. Roger King at Bagram air base, the U.S. military headquarters in Afghanistan. A patrol sent to investigate captured the men and recovered a grenade launcher, King said.

In the same area Thursday, coalition forces detained 12 people. King said the attack on the base happened on Friday, but he would give no further details.

Forces also uncovered two weapons caches on Friday near Zormat, in Paktika province. The weapons included mortar ammunition, a rocket-propelled grenade launcher and anti-personnel mines, King said.

U.S. special operations forces on patrol in the southern province of Zabul on Friday found mortar rounds, five rockets, and grenades for a rocket-propelled launcher in a partially collapsed cave, King said.

In the village of Nariza in Paktia province on Thursday, seven women were found to be carrying nine grenades for a rocket-propelled launcher under their burqas, King said. The munitions were taken away, but the women were not detained, he said.

The weapon recoveries were part of Operation Mountain Sweep, aimed at capturing or killing Al Qaeda members and supporters and keeping them out of the area.

The military says the operation, which began Sunday, is comparable to Operation Anaconda, the last major battle in March, when more than 2,000 U.S. and coalition troops forced Al Qaeda fighters and their Taliban allies to flee their hideouts in southeastern Afghanistan.