Hertfordshire Constabulary has issued a warning after two men died after taking what is believed to be 'Superman' ecstasy tablets.

The tablets are red, triangular in shape and embossed with an 'S', described as being similar to the 'Superman' logo.

The warning comes after the deaths of two young men in Ipswich and West Mercia over Christmas and the New Year.

Detective Superintendent Paul Maghie, head of the safeguarding command at Hertfordshire Constbulary, said: "I would like to emphasise that we have no intelligence to suggest that these pills are in circulation in Hertfordshire at this time but this picture could change and we have a duty to protect people from harm.

"These tablets are thought to contain large doses of PMMA, which has different effects to the common ecstasy pill, MDMA. PMMA can take different times to take effect which often results in users taking more of it, often resulting in serious harm.

"There is no way of knowing what is in any pill, therefore it is safest to steer clear altogether. Police forces across the country are doing all they can to reduce the risk of further serious injury or deaths linked to this particular ecstasy pill.

"We do not know how many are still in circulation, so I urge people not to take these drugs and anyone in possession of them to hand them in to police or partner agencies."

Anyone in possession of the drug is asked to surrender it to police in person or by calling 101, or you can call the same number if you have information about the supply of this or other illegal drugs.