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.
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Armed police were pictured in Littlehampton Road, Worthing. Photo: Eddie Mitchell SUS-211220-080759001
Photo: EDDIE MITCHELL
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Armed police were pictured in Littlehampton Road, Worthing. Photo: Eddie Mitchell SUS-211220-080736001
Photo: EDDIE MITCHELL
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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