Four people have been hospitalised after taking an unknown substance at a Belfast nightclub.
One of those being treated, a 22-year-old man, is understood to be in a critical condition. Police said the four took the substance before becoming ill.
The condition of a second man aged 19, a 20-year-old woman and a 17-year-old girl is not believed to be life- threatening. Police have appealed for information about the incident at Myntnight club at Dunbar link in the city.
Officers said the events were a reminder of the dangers of drug use.