Armed thieves stole a three-figure sum of cash during an attack which left a security van guard with a suspected broken jaw.

Three men approached two guards who were delivering money to Nationwide in Bank Street, Braintree, at around 4am today.

One of the suspects had a hammer and struck one of the guards with it, while both victims were punched leaving one with a suspected broken jaw.

They managed to fight the men off but a three-figure sum of cash was stolen.

The men were all described as wearing dark clothing and had their faces covered.

Chief Inspector Janette Rawlingson, District Commander for Braintree and Uttlesford, said: “This was a despicable, targeted incident and I urge anyone with information to come forward.

“The victims showed extraordinary bravery in a challenging situation and, having spoken with them this morning, they remain in good spirits and are being supported by our officers.

“Officers were on scene within five minutes of the initial call, and continue to work on several lines of enquiry to progress our investigations.

"We are particularly keen to speak to any witnesses who may have seen any activity on Bank Street or the adjoining Coggeshall Road at this time.

“I would like to thank the local community for being patient during any disruption this morning in the area near to Bank Street."

The Nationwide branch will remain closed for the rest of Thursday but is expected to open as normal tomorrow.

A spokesman for Nationwide said: "We are aware of an incident on the external ATM at our Braintree branch.

"This happened in the early hours of the morning at 5am, and no Nationwide employees or members were involved.

"We are liaising with the police and G4S as they carry out their investigation.

"The branch will open as normal tomorrow."

Gareth Skinner, head of operational risk for G4S Cash Solutions, said: "In the early hours of this morning, two of our employees were the victims of a vicious attack during a routine service at a branch of Nationwide in Braintree.

"Both sustained injuries and are currently recovering at home.

"We are working with the police who are investigating this incident and encourage anyone with information to contact them so that the offenders can be brought to justice."

Anyone with information about the incident should call 101 quoting incident 115 of September 27.