The Department of State has warned US citizens worldwide about possible retaliation attacks after the death of a radical US-born cleric in Yemen.
Anwar al-Awlaki, along with several other militants, was killed early Friday in eastern Yemen in what Yemeni newspapers say was a suspected CIA drone strike.
"The death of Awlaki, in the near term, could provide motivation for anti-American attacks worldwide from individuals or groups seeking to retaliate against US citizens or interests because of this action," the US Department of State said.
"Awlaki's standing as a pre-eminent English-language advocate of violence could potentially trigger anti-American acts worldwide to avenge his death," the department's travel alert reads.
The warning will remain in place until Nov 30.
The FBI and the Department of Homeland Security have also warned about possible retaliation from extremists on the US territory.