The Pentagon announced that it is raising the security levels at its military bases across the nation.

Pentagon spokesman George Little says the boost in the “force protection condition” is not due to any specific threat or planned attack, according to the Associated Press.

It’s because Al Qaeda has previously plotted to attack on on anniversaries, and that materials seized at the compound where Osama bin Laden was killed had mentioned the anniversary of Sept. 11, said the report.

Most U.S. military installations abroad have already been operating at a higher security level.