DETECTIVES cordoned off a York street for nearly ten hours after reports that a suspicious device had been placed under a car.

Fifteen City of York Council employees and 11 residents were evacuated from 22 The Avenue, in Clifton, following the discovery of the suspect package.

Dozens of police officers sealed off the scene, and the A19 at Bootham, as bomb disposal experts from Catterick Garrison were called in to examine the device.

A 43-year-old man from the city was later arrested in connection with the incident. He remained in custody at Fulford Police Station today, police said.

Bootham was reopened about four hours later, but the area around the suspect device remained sealed off until early evening.

Meanwhile, a team of officers, some armed, raided a flat at Winchester House, in Holgate, in connection with the arrest.

The suspicious package caused widespread disruption in a busy part of the city. Motorists travelling out of the city were diverted down Burton Stone Lane and A-level students taking their physics and music exams at St Peter's School were delayed by 40 minutes.

The alarm was raised at about 9.30am yesterday morning. Bootham was sealed off until about 2pm, but The Avenue remained closed until early evening. The package was made safe by Army experts at about 3.30pm, but police investigators then carried out a finger-tip investigation of the scene.

Inspector Philip Metcalfe, of York police station, said: "There have been reports of an unexploded device on The Avenue. We cordoned the area off and bomb disposal from Catterick Garrison investigated that device."

Acting detective inspector Ian Dyer, at the scene at Winchester House, said: "There was an incident in Bootham today where a device was placed under a car. This incident is linked to it and is in connection with an arrest of a suspect for that offence."

He would not confirm whether the flat was the home of the 43-year-old arrested man.

Richard Smyth, St Peter's School head teacher, said: "I have had about 300 pupils in the main building who have been cooped up waiting for the all clear.

"Our pupils taking physics and music A-levels were affected and their exams had to be put back by about 40 minutes. It was not the ideal preparation, but we can inform the exam board of what had happened."

City of York Council confirmed the evacuations from the site, which housed a residential rehabilitation unit for people with mental health problems. It said: "The Assertive Outreach Team employed by Selby and York Primary Care Trust is also based there and was also evacuated," she said. All of the residents of the unit were taken to Sycamore House, which is a day centre for mental health patients."

Updated: 10:31 Tuesday, June 28, 2005