New Delhi: In a concerning incident, several prison inmates in the United Kingdom were hospitalised after some inmates spiked the food served in the premises with a drug.

Raising concerns about security lapses within the high-security facility, the incident was reported at a high-security prison, HMP Swaleside, in England’s Kent, a news outlet reported.

The Criminal Justice Workers Union (CJWU) termed the incident as 'mass poisoning'. According to media reports, inmates working in the staff canteen are suspected of spiking a 'staff-special curry' with Spice, a synthetic cannabinoid.

Popular for housing dangerous criminals, HMP is now under investigation after prisoners working in the staff canteen are suspected of spiking a 'staff special-curry' with spice, a synthetic cannabinoid, which can lead to anxiety, paranoia, and seizures.

As many as 25 prison staff members were impacted in the security lapse.

The affected people expected different symptoms including breathing difficulties and raised heart rates.

After receiving the information, nine ambulances were rushed to the spot on May 9. The five prison officers were later discharged.

A jail inspection conducted earlier had raised concerns of high violence levels and readily available drugs.  The security lapse is expected to spark discussions about stricter rules for inmate work programmes.