London, Nov 25 (IANS): British authorities re-opened London's Oxford Circus subway station on Friday after armed police responding to reports of a shooting found no evidence of gunplay or any suspicious activity.

The incident, which began at 4.38 p.m., was treated as a potential terrorist attack, the Metropolitan Police said, Efe news agency reported.

Police acted after receiving a spate of emergency calls from people saying that shots had been fired on Oxford Street and at the Oxford Circus underground station, the Met said.

"Given the nature of the information received, the Met responded in line with our existing operation as if the incident was terrorism, including the deployment of armed officers," the force said in a statement.

Passengers fled from the station and onto the surrounding streets, spurring panic.

"Officers working with colleagues from British Transport Police carried out an urgent search of the area. No causalities, evidence of any shots fired or any suspects were located by police," according to the statement from the Met.

Once police gave the all-clear, the underground station resumed operation and riders and pedestrians who had taken refuge in nearby pubs and shops re-emerged.