Littlehampton Road was reportedly closed whilst officers were at the scene.
Pictures show police using drones to assist the emergency operation.
According to an eye-witness, the police dog unit was also in attendance.

1.
Armed police were pictured in Littlehampton Road, Worthing. Photo: Eddie Mitchell SUS-211220-080759001 Photo: EDDIE MITCHELL

2.
Armed police were pictured in Littlehampton Road, Worthing. Photo: Eddie Mitchell SUS-211220-080736001 Photo: EDDIE MITCHELL

3.
Armed police were pictured in Littlehampton Road, Worthing. Photo: Eddie Mitchell SUS-211220-080723001 Photo: EDDIE MITCHELL

4.
Armed police were pictured in Littlehampton Road, Worthing. Photo: Eddie Mitchell SUS-211220-080711001 Photo: EDDIE MITCHELL