Fifteen people were hospitalised and an emergency situation declared in the southeastern Serbian city of Pirot following an ammonia leak caused by a cargo train derailing nearby, local media reported.

Among those taken to hospital in nearby Nis with symptoms of poisoning was one child, the reports said. No one was in a life threatening condition, they added.

The 20-wagon train was carrying ammonia from Bulgaria’s Agropolychim to Serbian fertiliser producer Zorka Eliksir, located in the town of Sabac, 90 kilometres west of Belgrade.

The media reports said that two wagons had left the tracks on Sunday afternoon and turned over, causing one to leak.

Infrastructure minister Goran Vesic said the poor condition of the rail tracks, which were scheduled for repairs, was the cause of the accident.

Nova S news web portal reported that there was a fog and strong ammonia smell in Pirot on Monday morning.

Schools and kindergartens were closed due to the emergency situation and people were advised not to go out if not necessary.