More than a third of all Belfast Bikes are currently out of action due to either theft or vandalism, the city council has said.

It added that the future of the bike hire scheme is now in jeopardy.

A recent spate of attacks has meant 210 of the 576-strong fleet are not in service, leading to a “severe impact” on users.

There have been many cases of “mindless vandalism”, the council said, while in one case a bike was sawn in half.

It is costing the scheme almost £1,800 per month.

Lord Mayor Brian Kingston said: “We have to address the problem of antisocial behaviour and put measures in place to safeguard the scheme.”

Since its launch in April 2015, the scheme has proven a success with almost 5,000 annual members and over 5,000 casual subscribers clocking up in excess of 405,000 journeys.

But over the Easter weekend alone, 19 bikes were stolen - six of which were recovered - while a further eight were vandalised.

Some of the bikes are said to be stolen for personal use.

Police and the council are appealing to bike users, and the public in general, to report theft and vandalism to the scheme operators, or bring it to the attention of the police.

Sergeant Pete Cunningham said: “We would appeal to anyone who witnesses any instances of theft or vandalism to the bikes to report this to police immediately so that we can address the issue and deal with those who are responsible.

“Please contact the PSNI by calling 101 or 999 in an emergency.

“Or, if you would prefer to provide information without giving your details you can contact the independent charity Crimestoppers and speak to them anonymously on 0800 555 111.”