A FIRE in a city office block, which caused chaos on Tuesday morning, is being treated as suspicious.

A police spokesman said investigators had sent material found at the scene of the fire in Newcastle to forensic experts for examination.

Hundreds of workers were turned away from their offices, and morning rush-hour traffic ground to a halt, as about 80 firefighters and 17 fire engines tackled the blaze in Pilgrim Street, on the Newcastle side of the Tyne Bridge.

Firefighters were called to the 18-storey Cale Cross House by police, who noticed smoke coming from the building at 3.20am. The fire broke out in storage offices shared by Robert Muckle Solicitors and another, unnamed, owner.

Firefighters with breathing apparatus worked in teams of four in rotation to tackle the blaze from inside the building.

A spokesman for Northumbria Fire Brigade said last night that the damage to the office had been confined mainly to the seat of the fire in a 10m by 10m room, with some smoke damage caused to the next floor.

Anyone who may have seen anything unusual in the area before 3.20am on Tuesday has been urged to contact Newcastle City CID on 0191-214 6555