Nigerian President Muhammadu Buhari on Monday held an emergency meeting with security chiefs, who played down any increased threats after the US embassy warned of potential attacks on the capital. Following the Abuja meeting, the presidency said Buhari was flying to London on Monday for regular medical checkups, the latest overseas medical trip for the 79-year-old former army chief. The US embassy has warned of a heightened risk of “terrorist attacks,” prompting the evacuation of some diplomatic families and similar advisories from the UK, Canada and other missions. National Security Adviser Babagana Monguno on Monday dismissed any “illusion” about heightened insecurity after the meeting with Buhari. “It is false, it is irresponsible for anybody to give that signal,” he told reporters. “We are working with our foreign partners in a responsible way and Nigerians should go back to their normal daily undertakings without being put in a situation of fear.” Nigeria’s overstretched military is battling jihadists, criminal gangs and separatist groups in different regions of Africa’s most populous country.