Several U.S. military bases in Europe have been placed on heightened alert over possible terrorist attacks, with Army officials elevating their protection level to condition “Charlie” until further notice.

Threat condition “Charlie” indicates military officials received intelligence indicating some form of terrorist action or targeting of U.S. personnel or facilities is likely, according to the Army’s website.

Some U.S. bases in Europe issued community alerts, including the Army’s Rheinland-Pfalz and Ramstein Air Base, which form the largest U.S. military communities overseas.

On Sunday, officials with U.S. European Command would not detail what prompted the decision to raise the security levels, telling news outlets that they are “constantly assessing a variety of factors” that play into the safety of overseas U.S. military communities.

“As part of that effort, we often times take additional steps to ensure the safety of our service members,” military officials said in a statement.

However, European officials have warned of potential terror threats ahead of the Paris Olympics set to begin this month and the current European soccer championship being held in Germany.

• Mike Glenn can be reached at mglenn@washingtontimes.com.