Three mortar rounds exploded near U.S. troops stationed in eastern Afghanistan, but no injuries were reported, a U.S. military spokesman said Tuesday.

Maj. Bryan Hilferty said the shells were fired Monday several hundred yards from U.S. forces in Gardez, about 60 miles south of the capital, Kabul.

Hilferty declined to say whether U.S. forces had returned fire, but said the troops went "out in that vicinity ... and had an encounter with people there."

"We are continuing to investigate but it's hard to tell in this country if that means they're attacking us," Hilferty said.

"Three mortar rounds in this country is not a particularly big deal," he said.

Also Tuesday, international peacekeepers said 10 Afghans were brought to hospitals after walking into a minefield near Kandahar, in southeastern Afghanistan.