LASER pen louts were warned last night that police will use the full weight of a new law if they try to dazzle pilots in Oxfordshire’s skies.

New legislation makes simply shining a light at an aircraft to dazzle a pilot a criminal offence.

Previously police could only charge them with endangering an aircraft, which they found more difficult to prove.

They hope the new law will mean more people are prosecuted.

There have been 10 incidents locally of lasers targeting pilots in the past 18 months, but only one person was caught and convicted.

Pilots flying in the dark can be temporarily blinded by the lasers because their cockpits are filled with dazzling light.

Insp Steve Bridges, of Thames Valley Police operational support, said: “Shining a laser at an aircraft is extremely dangerous, and anyone doing this will be dealt with severely.

“This is not just a childish prank – you could potentially kill hundreds of people by causing the aircraft to crash.

“If you witness a laser being shone at an aircraft, please contact us immediately, just as you would if you saw any other crime in progress.

“Lives are in danger, and the sooner we can get there, the better.”

In August, Jamir Ali admitted shining a laser at a police helicopter from his house in Leon Close, East Oxford.

Ali was ordered by Oxford magistrates in December to do 200 hours unpaid work and pay £150 costs.

The 19-year-old apologised to the court and said: “My laser pen days are definitely over.”

There have been reports of lasers targeting aircraft across the county including in Oxford, Brize Norton and Kidlington.

Nationally, there were 737 reports of people attempting to dazzle pilots in 2009, compared to 206 in 2008 and just 29 in 2007.

Mr Bridges added: “Some of the previous cases have not been investigated because we could not prove they had caused any danger.

“In Oxfordshire, we have military aircraft, aircraft at Oxford airport and police helicopters targeted.”

Some lasers available to buy on the Internet have a range of two miles.

Police are now speaking to online auctions sites such as eBay to limit their availability.

Mr Bridges said: “We are trying to make them aware, should they supply items which might be used for these purposes, they need to ensure correct policies are in place.

“If an investigation does take place then clearly we will be looking into where the laser was purchased.”

Anyone caught shining a laser at an aircraft can now be fined up to £2,500.