Two U.S. Marines were killed Sunday in intense fighting in eastern Afghanistan, the U.S. military said Monday in the latest indication of renewed clashes with suspected Taliban holdouts.

The firefight erupted in Jalalabad, about halfway between the Afghan capital of Kabul and the Pakistani border city of Peshawar. U.S. forces killed around two dozen fighters in the five-hour clash, the military said.

In a pair of statements released by Combined Forces Command-Afghanistan, the military said the Marines had acted on intelligence about enemy locations and “an engagement ensued.”

The names of the dead Marines are being withheld until next of kin is notified.

U.S. military officials said the battle began with insurgents using small arms and rocket-propelled grenades. One group of fighters fled to a cave while another group headed for a village.

The Marines called in air support, with Army A-10’s firing on the fighters in the cave. The two Marines were killed when their unit swept through the cave after the aerial attack.