Police in the North are investigating whether eight sudden deaths are linked to drugs.
Seven of the fatalities happened in the greater Belfast area, while one occurred in the northwest.
Tjhose who died were aged in their 20s and 30s.
Police are warning people to be particularly careful if they are offered green-coloured tablets with a logo of a crown or castle on them.
Unmarked white pills, which have not yet been tested but may be ecstasy, could also be involved in the deaths along with alcohol.