Taser stun guns, which incapacitate people by delivering 50,000-volt electric shocks, have been fired by police in Oxfordshire for the first time.

The Taser delivers a 50,000-volt shock Tasers, which shoot barbs resembling fish hooks into skin or clothing, have been used twice in the past fortnight to bring incidents to a conclusion without serious injury, said Thames Valley Police.

They have only been fired 13 times in total across the country since being introduced in April 2003.

A 20-year-old man was shot with a Taser following reports of an incident involving swords being wielded, shortly before midnight on Sunday, in James Street, east Oxford. A suspect was arrested.

This followed a Taser being used on a 35-year-old man outside Oxford's Westgate shopping centre, on February 15, at about 5pm. The man was on day release from a mental hospital in London, but got away from his carer.

Firearms officers equipped with Tasers have been deployed to several incidents since the stun guns were introduced in Oxfordshire.

On two occasions, the Taser's 'red dot' laser sight was trained on suspects, but it was not fired.

Oxford police spokesman Kate Smith said: "We have found that it's having a deterrent effect and helps bring potentially dangerous situations to a safe conclusion."

The Independent Police Complaints Commission is informed each time a Taser is fired.

But human rights group Amnesty International is worried that Tasers might be be used simply to inflict pain.

Amnesty spokesman Steve Ballinger said if they were used, they should only be deployed by trained firearms officers -- as they are at present in the UK -- and should not become a "standard policing tool".

"Tasers can kill, so they should be treated as a lethal weapon," he said.

Last September, the Association of Chief Police Officers welcomed an extension to a trial of Tasers, allowing them to be used by forces across the country.

The association said Tasers had been successful in bringing incidents involving armed or violent offenders to an end safely.

They are viewed as a less lethal alternative to shooting people with conventional firearms.

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