The mobile system was used to check for drugs and weapons

The force said it was the first in the North West to operate the x-ray, which is similar to those used at airports.

It was used close to the busy Concert Square and Church Street areas of the city over the weekend.

Ch Insp John Roy, of Merseyside Police, said about 10 arrests were made as a direct result of the device being used.

Deterrent effect

The system is designed to reassure the public and identify anyone carrying drugs or weapons.

Anyone avoiding police officers or acting suspiciously was asked to walk through the scanner on Friday and Saturday night.

Mr Roy said the device should make people think twice about bringing illegal items into the city centre.

"I think it was highly successful," he said.

"What we found were a number of people in possession of weapons such as knives.