WASHINGTON, Oct 19 (Reuters) - U.S. troops have been repeatedly attacked in Iraq and Syria in recent days, U.S. officials said on Thursday, as Washington is on heightened alert for activity by Iran-backed groups with regional tensions soaring during the Israel-Hamas war.

President Joe Biden has sent naval power to the Middle East in the past two weeks, including two aircraft carriers, other warships and about 2,000 Marines.

There has been an uptick in attacks on U.S. forces since the conflict in Israel broke out on Oct. 7 when Palestinian militants from Hamas attacked southern Israel. On Wednesday, a drone hit U.S. forces in Syria resulting in minor injuries, while another one was brought down.

During a false alarm at Al-Asad airbase in Iraq, a civilian contractor died from a cardiac arrest.

Earlier this week, U.S. forces thwarted multiple drones targeting troops in Iraq. On Thursday, drones and rockets targeted the Ain al-Asad air base, which hosts U.S. and other international forces in western Iraq, and multiple blasts were heard inside the base.

Rockets hit another military base hosting U.S. forces near Baghdad's international airport, Iraqi police said on Thursday, without providing further details.

"While I'm not going to forecast any potential responses to these attacks, I will say that we will take all necessary actions to defend U.S. and coalition forces against any threat," Pentagon spokesman Brigadier General Patrick Ryder told reporters on Thursday.

"Any response, should one occur, will come at a time in a manner of our choosing," Ryder said.

A U.S. Navy warship traveling near Yemen on Thursday intercepted missiles and several drones that were launched by what Ryder said was the Iran-aligned Houthi movement, though it appeared that the projectiles were potentially heading in the direction of Israel.