An Air France flight was forced to make an emergency landing in Kenya after a fake bomb was discovered onboard.

The Boeing 777 was flying between Mauritius and Paris when it was evacuated at Mombasa airport after a suspicious device was found in a toilet.

The BBC reports that airline’s chief executive Frederic Gagey later said the device had been made of a cardboard box, paper and a timer.

The plane was carrying 459 passengers and 13 crew. Reports suggest four people have been arrested in relation to the incident and are being questioned by Kenyan police.

Gagey said there had been no issues with security checks in Mauritius because the device contained no explosives so wouldn’t have been detected.