Police issue drug warning after four people overdose at Sydney party

Four people have been taken to hospital with suspected drug overdoses in Sydney's south.

Police say three men and a woman took a drug sold as ecstasy at a house party in the Cronulla area.

Aged between 20 and 22, they were treated in Sutherland Hospital early this morning.

Police believe the group all ingested the illicit drug in the form of a small blue pill, with a "scissors" logo stamped on it.

Three people were later released but a 20-year-old man remains in hospital under observation.

The incident follows another case where four men in Sydney's CBD were also treated this week for a suspected drug overdose.

NSW Ambulance Paramedics treated the men separately on Monday when they were called to a George Street nightclub four times between 7pm and 10pm.

Police say the men took the drug gamma-hydroxybutyric acid (known as GHB).

Investigations are underway for both cases.