The United States Embassy in Nigeria has alerted its citizens about a potential security threat linked to American locations in the country.

In a notice released online, the embassy advised U.S. nationals to be extra cautious around its offices in Abuja and the consulate in Lagos. The warning also includes schools connected to the United States.

While officials did not reveal where the threat might be coming from, the embassy encouraged Americans in Nigeria to avoid predictable routines, remain aware of their surroundings and stay away from crowded areas or demonstrations.

Citizens were also urged to keep their phones charged, review their personal safety plans and use different travel routes when moving around.

The advisory arrives at a time of rising global tension involving Iran, the United States and Israel following recent military confrontations.

In Nigeria, the situation has coincided with protests by members of the Islamic Movement in Nigeria, who condemned the reported killing of Iran’s Supreme Leader, Ali Khamenei.

The embassy said the alert is intended to keep American citizens informed and encourage precautionary measures while in the country.