Two men have been charged with terror offenses after police raided five properties earlier this month and arrested four on suspicion of plotting a Christmas terror attack.

Farhad Salah, 22, from Sheffield and a 31-year-old man from Chesterfield have been charged with 'Engaging in the preparation of an act of terrorism' and will appear before Westminster Magistrates on Friday.

They were among four men arrested on December 19 in Derbyshire and South Yorkshire as specialist counter terrorism police officers raided five properties following an 'Islamist related' investigation.

A 22-year-old man from Sheffield and a 31-year-old man from Chesterfield have been charged with 'Engaging in the preparation of an act of terrorism'. They were among four men arrested on December 19 in Derbyshire and South Yorkshire as specialist counter terrorism police officers raided five properties (pictured above) following an 'Islamist related' investigation

Anti-terror police working with MI5 arrested the four men on December 19 in raids that forced people to evacuate their homes and placed schools on lockdowns

Terrified residents described hearing explosions during the dramatic early morning raids on homes, offices and a community centre. Pictured above, a police officer investigates during one of the raids

A 36-year-old man from Sheffield remains in custody, while a 41-year-old man, also from Sheffield, was released on Saturday.

Assistant Chief Constable Bill McWilliam said: 'Together with South Yorkshire Police we continue to work closely with partners and communities to reassure local people and protect the public.

'I would like to remind people to remain vigilant, if you see or hear something that could be terrorist related, act on your instincts and call the anti-terrorist hotline on 0800 789 321. In an emergency dial 999.'

Anti-terror police working with MI5 arrested the four men on December 19 in raids that forced people to evacuate their homes and placed schools on lockdowns.

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

Two other men were arrested in the December 19 raids (pictured above). A 36-year-old man from Sheffield remains in custody, while a 41-year-old man, also from Sheffield, was released on Saturday

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

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

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

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

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

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

Police also sealed off the Fatima Community Centre (pictured above) in the Burngreave area of Sheffield

Following the raid at the Fatima Community Centre, part of a door remained shattered on the ground

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.

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

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.

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.