SHEFFIELD TERROR PLOT: What we know so far

Three men have been arrested in Sheffield this morning on suspicion of terror offences

Three men from Sheffield are being held this morning on suspicion of terror offences after a series of dawn raids in the city.

Here is what we know so far:

- Three men, aged 22, 36 and 41, were arrested in a series of dawn raids carried out simultaneously at addresses in Sheffield this morning.

- A fourth man, aged 41, was arrested in Chesterfield after another raid.

- The raids, carried out by specialist officers from the North East Counter Terrorism Unit, were carried out at the suspects' homes.

- The men have all been taken to a police station in West Yorkshire for questioning.

- All four men are being held on suspicion of being concerned in the commission, preparation or instigation of acts of terrorism under section 41 of the Terrorism Act 2000.

- The North East Counter Terrorism Unit said the arrests were 'intelligence led and pre-planned as part of an ongoing investigation'.

- Four homes in Sheffield were raided in total - two in Burngreave, one in Meersbrook and another in Stocksbridge. They remain under police guard while officers search them.

- One of the arrests was made at a terraced property in Shirebrook Road, Meersbrook, at around 5.30am.

- Neighbours who heard officers raid the house said they heard a loud bang, or an explosion, which is believed to have been the sound of the door being forced open.

- Residents said they saw a man being led away by officers before more police officers arrived.

- Armed officers are at the property.

- The North East Counter Terrorism Unit said it recognises that 'local people may have concerns as a result of this activity'. A spokesman said: "We would ask people to remain alert but not alarmed and we are grateful for the assistance and understanding of people locally."

- The Royal Logistics Bomb Disposal Team was called to Chesterfield earlier this morning, in a move believed to form part of the terror operation.

- A house between the Spar store, on Sheffield Road, Whittington Moor, and the Whittington Moor roundabout, was raided.

- Road closures were put in place while officers raided the property.