The mother of a man killed in an armed raid on a Worcestershire post office said today he had died protecting those he loved.

Judy Hodson-Walker said her family was devastated by the death of her 29-year-old son Craig, who was shot in the chest during the attack on their shop in the Fairfield area of Bromsgrove yesterday morning.

His father Ken, 56, was shot in the leg and is in a stable condition in hospital after surgery.

"We are devastated at the death of our beautiful boy who died protecting the people that he loved," she said in a statement released by police.

West Mercia Police said they now believed four men were involved in the attack.

Three men wearing balaclavas and armed with a handgun and a sledgehammer entered the shop while another, his head concealed by a hooded jacket and scarf, waited outside in a silver Volkswagen Golf.

The car was found abandoned nearby after the raid. Police said it had been stolen from Solihull on New Year's Eve and asked for anyone who had seen it between then and the raid to come forward.

A police spokesman said more than 100 detectives and police staff were working on the case.

"I would like to assure people that we are doing absolutely everything that can be done to ensure that the men responsible for this horrific crime are arrested and brought to justice as soon as possible," he said.

"We will leave no stone unturned."