(CNN) -- The United States believes one of its armed helicopters was shot down over Afghanistan on Wednesday, killing both crew members on board, a U.S. military official said.
NATO's International Security Assistance Force issued a statement saying that two ISAF members died "following a helicopter crash in eastern Afghanistan today."
"The cause of the crash is currently under investigation," ISAF said. "... At this time it is too early to speculate on the cause of the incident."
Operational reporting indicates there were no civilian casualties or damage to civilian property, ISAF said.
"It is likely that the helo today was brought down due to enemy small arms and RPG fire," the U.S. military official said. The chopper was a U.S. Army OH-58 Kiowa Warrior reconnaissance helicopter. It went down over Ghazni province.
In an e-mail, the Taliban claimed responsibility for downing the helicopter, saying a rocket was used.
"After the rocket hit it, the helicopter came down and took fire," said the e-mail, sent by Taliban spokesman Zabiullah Mujahid.
CNN's Barbara Starr in Washington and Masoud Popalzai in Kabul contributed to this report.