On Sunday, the United States and Britain issued a warning over a potential terrorist assault in Abuja, the federal capital of Nigeria, with particular emphasis on targeting government structures, houses of worship, and educational institutions.

Nigeria is mostly facing an Islamist insurgency in the northeast, but in July, the Islamic State claimed credit for a raid on an Abuja jail that resulted in the release of over 440 prisoners, sparking concerns that terrorists were leaving their strongholds.

The U.S. Embassy in Nigeria said “there is an elevated risk of terror attacks in Nigeria, specifically Abuja” and added that shopping malls, law enforcement facilities and international organisations were among places at risk.

“The U.S. Embassy will offer reduced services until further notice,” the embassy said in an alert to citizens in Nigeria.

The United Kingdom government warned that its citizens in Nigeria should stay alert due to an “increased threat of terrorist attack in Abuja.”

“Attacks could be indiscriminate and could affect western interests, as well as places visited by tourists,” it said.

Insecurity, which has spread across Nigeria, is a major issue for voters when they go to the polls next February to elect a new president to succeed President Muhammadu Buhari.

Nigeria’s foreign affairs ministry was not immediately available to comment.