Armed French border patrol agents have caused anger by crossing into Italy and entering a migrant clinic at a railway station.
Italian politicians have summoned the French ambassador Christian Masset to Rome over the controversy, in which five officers forced a Nigerian migrant to undergo a urine test.
French representatives have said the country has the right to use the facility at Bardonecchia train station in the city of Turin, citing a 1990 agreement.
But Italy has said it told French customs authorities this month that the train station room was now off-limits, and added that talks had been scheduled in Turin on 16 April to discuss the situation.
They said this was because the humanitarian aid group Rainbow4Africa was there to provide care and counselling for migrants seeking to make a dangerous Alpine crossing into France.
The migrant clinic is located roughly half a mile inside the Italian border.
Rainbow4Africa raised the alarm at what it called a “raid” on Friday night.
The organisation said in a statement: “French border agents entered – armed – the clinic run in Bardonecchia, forcing a migrant to a urine test and intimidating our doctor and the mediators and lawyers.”
Rainbow4Africa added that the French officers “seriously interfered” with the work of a non-governmental organisation.
The aid group added that France should change its strict policy on rejecting migrants.
Italy has received around 600,000 migrants in the past four years.
The French government has said officials asked for permission to enter the site and were allowed in.
It added that the customs officials boarded a train travelling into Italy because they suspected a Nigerian passenger was carrying drugs.
The urine test result later came back as negative.
A volunteer who saw the incident told Sky TG24 that the Nigerian had Italian identity papers and a valid Paris-Naples train ticket.
The French budget ministry said its border agents asked to use the facility to respect the rights of the man on the train.
The Italian foreign ministry said that during its consultations with the French Ambassador it lodged its “firm protest” over the “unacceptable” behaviour of the French agents, and warned that border cooperation was now undermined.
Bardonecchia Mayor Francesco Avato said the border patrols had no right to enter the facility, which he said the city operates with Rainbow4Africa as a “neutral” space to try to persuade migrants not to make the crossing.
French and Austrian border patrol agents have stepped up their checks along Italy’s northern border to prevent migrants from entering their countries on trains, trucks or even on foot across the snow-covered mountains, an option that more and more desperate migrants are attempting despite the cold and danger.