Police are searching for witnesses who saw two men on an off-road bike before and after they stole money from a security van.
The two men were seen riding the scrambler-style bike "erratically" along Woodfield Street in Morriston on Thursday afternoon.
Shortly after, the bike stopped outside Halifax before the men escaped with cash from a security van which had been unloading money.
The thieves, who are described as being white and in their early 30s, rode off towards Morriston Cross.
South Wales Police is now urging any witnesses who saw the men on the bike in the area to get in touch.
A spokesman for the force said: "Officers investigating the theft of cash from a security van in Morriston on Thursday afternoon have appealed for witnesses who saw two people on an off-road bike in the area.
"The men were seen riding a white, scrambler-style bike erratically along Woodfield Street at about 12.40pm.
"The bike stopped outside Halifax and those riding it then made off with cash from a security van which was unloading the money.
"The bike was ridden off in the direction of Morriston Cross.
"The duo are described as white males in their early to late 30s. The rider was wearing a dark helmet and the pillion passenger wore a green-coloured helmet."
This is what happens next when someone reports a crime to police:
Anyone who might have witnessed the theft or has information about the men involved is asked to call 101, quoting reference 1900346602.
