Nigeria, March 10 -- In a notice released on Monday, March 9, the US Embassy in Abuja urged Americans living in or visiting Nigeria to exercise heightened vigilance and take precautionary security measures.

"The US Embassy in Abuja informs US citizens of a possible terrorist threat against US facilities and US-affiliated schools in Nigeria," the advisory stated.

The embassy advised US nationals to increase personal security awareness, avoid predictable routines and review safety and emergency plans with their families in order to mitigate potential risks.

The alert, however, did not specify the source of the threat or identify any group believed to be responsible, The News Chronicle gathered.

The advisory comes amid heightened global...