The charity Crimestoppers and The Association of Convenience Stores (ACS) are offering a reward of up to £5,000 for information leading to the arrest and conviction of the people responsible for the aggravated robbery of a Hampshire service station.

The incident happened on February 17 at around 4.25am at the Esso garage at Stoney Cross on the westbound carriageway of the A31.

One of two staff members working that morning was assaulted with a crowbar, and was treated for a head injury at Royal Bournemouth Hospital.

Three individuals are understood to have forced their way through the back door of the station, when the two employees were threatened, before one was attacked. Cash is believed to have been taken from the premises.

Dave Hunter, head of operations for Crimestoppers, said: “Nobody going into their place of work should feel unsafe, so it’s terrible to hear of these two employees finding themselves in such a vulnerable position.

“Both employees have been left badly shaken by their ordeal and one of them has ended up in hospital. This is not right. I would ask anyone with information from that morning, to do the right thing – speak up and help keep your community safe. Contact our charity anonymously and tell us what you know. We won’t judge. Won’t ask any personal details. We’ll just pass on what you know.”

ACS chief executive James Lowman said: “It’s unacceptable when people are attacked in this way, and we have to do all we can to bring to justice those who committed this violence. We hope this reward will help the police to get the information they need.”

Anyone with information on this robbery can contact Crimestoppers anonymously on 0800 555111 or through the non-traceable anonymous online form at www.crimestoppers-uk.org.