The United States has advised her citizens to review their travel plans to and within Nigeria.
The travel advisory followed the killing of Iran's top military commander Qassem Soleimani by American forces.
Soleimani was killed by an air strike at Baghdad airport early on Friday. At least six others were reportedly killed, including Iraqi militia commander Abu Mahdi al-Muhandis, an adviser to Soleimani.
Iran had vowed a "vigorous revenge" on those responsible for the killing.
The US Mission in Nigeria said though it had no specific threat information, it warned American nationals to be aware of their surroundings and alter their travel routes and times.
It asked them to stay alert in public places, including schools, hospitals, government facilities, places of worship, tourist locations, and transportation hubs.
A statement on its website, dated January 3, 2020, said "Due to recent world events, U.S. citizens should review their personal security measures.
"While we have no specific threat information, it is prudent to remind ourselves of the following personal security actions to follow on a regular basis.
"Actions To Take: Be aware of your surroundings; Keep a low profile; Stay alert in public places, including schools, hospitals, government facilities, places of worship, tourist locations, and transportation hubs.
"Review and alter travel routes and times to reduce time and place predictability; Avoid crowds and demonstrations; Exercise caution when walking or driving at night; Carry proper ID; Review your personal security plans; Monitor local media for updates; Review the Travel Advisory for Nigeria."