The U.S. Mission in Nigeria has warned its employees and citizens to avoid “non-official” visits to Nigerian military bases and government facilities.

In a statement published on its website on Sunday, the U.S. Mission in Nigeria cited “concerns arising from current global developments” as the reason for warning its citizens and employees to avoid visits to military bases and government facilities.

“Due to increased security concerns arising from current global developments, U.S. Mission Nigeria informs U.S. citizens that all U.S. embassy employees and their families are prohibited from non-official travel to a Nigerian military site or other government venue in Abuja at this time,” the statement reads.

The U.S. Mission further warned American citizens in Nigeria to “Stay alert in public places, with particular attention to locations and venues where Westerners, expatriates, and government officials frequent.”

It added, “Avoid large gatherings and consider limiting unnecessary travel. Avoid predictable routines. Familiarise yourself with emergency exits when you enter buildings. Review your personal security plans.”

This comes after a Boko Haram suicide bomber killed over 20 in Borno during the weekend. It also followed the U.S. bombing of Iranian nuclear facilities over the weekend.

Israel and Iran have been exchanging missiles for over a week. Israel had first struck Iran and its nuclear and military complex, killing the country’s top three military officials and six nuclear scientists.