Police have raided five properties and arrested four men on suspicion of plotting a 'Christmas terror attack'.

Specialist counter terrorism police officers kicked a door off its hinges as they arrested three men aged 22, 36 and 41, at addresses in Sheffield on suspicion of being concerned in the commission, preparation or instigation of acts of terrorism.

A 31-year-old man was arrested at an address in Chesterfield on suspicion of the same offence.

All four were arrested by anti-terror police working with MI5 in the 'Islamist related' investigation, with people evacuated from their homes and schools placed on lock down this morning.

Terrified residents described hearing explosions during the dramatic early morning raids on homes, offices and a community centre.

They saw bomb disposal officers removing 'packages' - which come amid chilling warnings from ISIS threatening to attack festive events in the UK.

Police have evacuated an area in Chesterfield, Derbyshire while bomb squad officers assess the scene

Police officers are guarding a flat on Verdon Street, in Sheffield, South Yorkshire after one of the raids

Police guard the Fatima Community Centre in Sheffield, South Yorkshire, after it was raided by counter-terror police

A spokesperson from the North East Counter Terrorism Unit (NECTU) has confirmed that police are now searching five addresses in an 'Islamist related' investigation. Pictured, police in King Street North in Chesterfield

TERROR ARRESTS: 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 31, 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

Five homes in Sheffield and Chesterfield were raided in total - including two in Burngreave, one in Meersbrook and another in Stocksbridge, and all remain under police guard

The Army's Bomb Disposal Unit is at the address in Chesterfield, and the area has been evacuated

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 Advertisement

A spokesperson from the North East Counter Terrorism Unit (NECTU) has confirmed that police are now searching five addresses.

One of the houses raided was in Shirebrook Road, Sheffield, where locals claim they heard an explosion at around 5.30am.

Residents said officers then arrived at the scene and carried out a search, and the house remains under police guard.

Five addresses in Sheffield - including one in the Meersbrook area, two in Burngreave and one in the Stocksbridge area - and another in Chesterfield, are being searched by police.

Police have also sealed off the Fatima Community Centre in the Burngreave area of Sheffield.

A large number of police vehicles are parked outside the two-storey building and officers are guarding the main entrance, which is cordoned off with tape.

It appeared that the main door to building is on the floor in pieces.

A further raid in Chesterfield at Whittington Moor led to Cavendish Junior School keeping children inside as a precaution.

One man who lives close to the raid in Brunswick Road said he was woken at 6am by three explosions in quick succession.

He said he thought one of the bangs came from the community centre but the others appeared to come from nearby flats.

The man said he looked out to see at least six men with rifles in camouflage and full body armour.

And a source told Sky News: 'We won't know exactly what we've got until we have finished searches of the suspects' properties and electronic devices.

'But the timing of the raids may be significant and the use of the bomb squad clearly shows what police thought they might find behind the door.'

Police guard an address on Shirebrook Road, Sheffield which was one of the properties raided

The Fatima Community Centre was being watched by officers throughout the afternoon

Officers smashed windows and doors to gain entry to the properties

The bomb squad put a cordon in place and evacuated residents in Chesterfield

Police at the scene of one of the raids in Chesterfield which appeared to involve a flat above a fish and chip shop

The bomb disposal squad was called out to handle 'packages' at at least one of the properties

One of the houses raided was in Shirebrook Road, Sheffield, where locals claim they heard an explosion at around 5.30am

PROPERTIES RAIDED Police have carried out five raids in the 'Islamist-related' investigation. While the NECTU will not reveal individual addresses, officers are known to have searched properties in: Shirebrook Road, Meersbrook, Sheffield Stocksbridge Gents Barbers in Stocksbridge, Sheffield Whittington Moor, Chesterfield Verdon Street, Burngreave, Sheffield Fatima Community Centre, on Brunswick Road, Burngreave, Sheffield Advertisement

He said: 'They were in full kit with the guns and everything. We're on the front line here.'

He said he saw them bring out one man and put him in a police van.

The man said the building used to be the local Irish club but was taken over about 10 years ago and is now used as a mosque and a community centre.

He said: 'There are people in there all hours of the day and night.'

Asked if he was surprised this had happened on his doorstep, he said: 'No'.

Simon Fox, 22, who lives near one of the raided properties, said: 'We have seen army, police from all over, we have seen a couple of packages being removed by the bomb disposal unit.

'You just don't expect this to happen in such a small town.'

Four addresses in Sheffield - with one in the Meersbrook area, two in Burngreave and one in the Stocksbridge area - and another in Chesterfield, are being searched by police. Pictured is the Fatima Community Centre in Sheffield

There is a heavy police presence in King Street, in Chesterfield as officers raid properties

ANTI-TERROR CHIEF WARNED OF CHRISTMAS ATTACKS Chris Phillips, who was once head of the National Counter Terrorism Security Office, has said there should be 'no surprise' if terrorists strike before December 25. He warned that it would be impossible for police to ensure the entire country's safety because of the sheer number of potential threats. His warning came after posters of Santa Claus kneeling before an ISIS executioner on London's Regent Street, and a jihadi with a bloody knife looking out over a Paris Christmas market with the Eiffel Tower in the background were shared online last month. Both images carried the message 'Soon on your holidays' in English, French, and German. The country's current threat level has seen more armed police on the streets and bollards erected on pavements to prevent vehicle attacks. Advertisement

A next door neighbour of the house in Shirebrook Road said he knew who lived next door and they were 'all nice lads.'

The man, who did not wish to be named, said: 'I heard a big bang, which turned out to be the charge they used to open the door.

'I then went to my housemate and we were watching the whole thing from out the window, we saw various armed special forces and the counter terrorism unit coming in and out and then the guy came out.

'I don't know the guys from next door very well but we have had fires in the past and they have come down, they seemed like nice lads, it's a shame really.

'I am shocked.'

A police spokesperson has confirmed that a loud bang heard by residents was not an explosion but a bang created when they were gaining entry.

Police confirmed all the properties are currently being searched and the men have been taken to a police station in West Yorkshire for questioning.

The arrests were intelligence led and pre-planned as part of an ongoing investigation by Counter Terrorism Policing North East.

The police raid in Chesterfield has led to a nearby primary school keeping children inside as a precaution

Police in Chesterfield: The arrests were intelligence led and pre-planned as part of an ongoing investigation by Counter Terrorism Policing North East

Police guard the Fatima Community Centre, on Brunswick Road, in Sheffield, South Yorkshire

A spokesman for the North East Counter Terrorism Policing Unit added: 'The men have been taken to a police station in West Yorkshire for questioning.

'The arrests were intelligence led and pre-planned as part of an ongoing investigation.

'Three properties in Sheffield and one in Chesterfield are currently being searched in connection with these arrests.

'We recognise that local people may have concerns as a result of this activity. We would ask people to remain alert but not alarmed and we are grateful for the assistance and understanding of people locally.

'Residents will be kept as informed as possible and we are grateful for their understanding, patience and support while these enquiries continue.'

A property in Shirebrook Road, Sheffield is being searched after it was raided in the early hours

A further raid in Chesterfield at Whittington Moor has led to Cavendish Junior School (pictured) keeping children inside as a precaution

Police confirmed all the properties are currently being searched and the men have been taken to a police station in West Yorkshire for questioning

South Yorkshire Police Superintendent for the Sheffield area Una Jennings said: 'I understand our local communities will have concerns about this morning's police activity but I want to offer my reassurance that we will continue to serve and protect the public of South Yorkshire.

'We work very closely with our colleagues at the North East Counter Terrorism Unit and we will ensure we maintain these strong links in order to provide a high level of service and delivery to everyone in our community. Public safety is our utmost concern.'

The operation was mounted as police and MI5 tackle a terror threat seen as unprecedented.

In addition to five attacks in London and Manchester, Home Secretary Amber Rudd revealed earlier this month that security agencies have foiled nine plots since the Westminster atrocity in March.

Police are pictured at the scene of the raid on the Fatima Community Centre today

Two bomb trucks were seen in the area this evening following today's police operation

A door appears to have been forced off its hinges during the raid

It is thought that the door was removed by police as they rushed into the premises

Counter-terror teams are running about 500 live investigations involving 3,000 individuals at any one time, while there is also a wider pool of 20,000 subjects of previous probes.

A woman, who did not wish to be named and lives opposite the property that was raided on Kings Road North, said: 'I was watching telly and saw police knocking on a neighbour's door.

'The next minute they were banging on my door and shouted, 'you have 10 minutes to get out, we're evacuating'. I was really panicking.

'It's a Syrian family who lives there, they didn't speak much.

'He definitely had children, he had a beard, and he dressed trendy. He had two little kids, one was in a pushchair. His wife had a headscarf, they kept themselves to themselves, really.'

In Meersbrook, retired Joan Miller, 63, said she was woken by a loud bang at 5.30am and looked out of her window to see plain-clothed armed officers in the street.

An officer is seen searching the Mermaid Fish Bar in Chesterfield following today's arrests

Police descended on the chip shop and are thought to have raided the flat above it

Ms Miller said: 'It was a very loud bang. It shook the house. I pulled the curtains and saw lots of armed men in the street, so I kept watching because that was quite extraordinary.'

Ms Miller and others in the street said they did not know who lived in the house opposite, which is in a dilapidated state.

She said: 'All sorts of different people have been living there.'

A man living near the Fatima Community Centre, on Brunswick Road, said he was woken by a three louds bangs in quick succession and then saw at least six men with rifles in camouflage and body armour.

He said he saw them bring out one man and put him in a police van.

The man said the building used to be the local Irish club but was taken over about 10 years ago and is now used as a mosque and community centre.

He said: 'There are people in there all hours of the day and night.'