Three stowaways have been discovered at a RAF airfield after a coach arrived at the site from France.
The men aged between 22 and 27 who said they were from Sudan were detained at RAF Waddington, near Lincoln, on Sunday and handed to Lincolnshire Police.
They are thought to have arrived on a coach bringing RAF staff home from training in France, the force said.
The Home Office said it would progress their cases in accordance with immigration rules.
The men have been handed over to the Home Office and if someone had no right to remain in the UK action would be taken to remove them, it said.
RAF Waddington has two main roles, electronic reconnaissance and battlefield surveillance and with six squadrons operating from it is one of the RAF's busiest operational airfields.
It started as a training base in 1916, according to the RAF website.