Youngsters are endangering lives by stealing supermarket trolleys and letting them loose down steep streets in Shipley.

Elizabeth Higgins, of Leeds Road, said children were taking Asda trolleys to hilly roads on the Windhill estate.

"They are taking them up the slope then letting them run from the top," she said.

"An elderly lady has already had a near-miss - they could cause an accident on Leeds Road. "This is not just a one-off. It is happening on a regular basis."

She has reported the problem to the store in Shipley and is calling for £1 deposit boxes to be installed on trolleys to deter youngsters from stealing them.

"The residents are sick of using their phone bills to ask Asda to come and collect them," she said.

"Since the store opened 24 hours it has become even worse. They are making a fantastic profit out of the people in the Shipley area and we are entitled to have something done about it."

The store, in Wellcroft, currently has deposit boxes on some of its trolleys, but not all of them, and customer services manager Jane Lovell Bearder said today the boxes were unpopular with customers. "We have had strong customer feedback that when customers come to the store, with two children, and have to park their car and then get a trolley, the last thing they want to be doing is finding £1," she said.

She said the problem was infuriating, particularly since the lost trolleys cost around £100 to replace.

The supermarket is now looking at other measures to prevent trolley thefts from the car parks.

"Shipley is not a particular hot spot but it sometimes happens, particularly in the school holidays," she said.

"We have colleagues patrolling the car park and we will continue to challenge people taking empty trolleys out of the car park. They are very expensive to replace and we don't like losing them.

"It is infuriating for the store, but also the customers as well as the residents. We do collect trolleys that have been found and it is great to have feedback from customers to find out where they are."

She said some stores had installed a 'cartronics' system which locks the wheels of trolleys if they are pushed out of the car park. The system, which is expensive to install, involves running a cable around the car park.

The wheels are fitted with a transmitting device and if pushed over the car park boundaries become immobilised. She said that was an option for the Shipley store but the company would monitor the situation first to see if the problem was long-running or just a spate. She said around three trolleys a week were going missing.

A police spokesman said any incidents of youths misbehaving with trolleys and putting people at risk would be taken seriously and investigated. Any witnesses should telephone Shipley police station on (01274) 537459.