A fourth man has been arrested under anti-terrorism laws, following a series of raids in Manchester and Bury.

The 31-year-old, who is believed to be of north African origin, was arrested at an address in Stretford, Greater Manchester, police said.

He was detained at around 1100 GMT under the Terrorism Act 2000.

Three other men, aged 30, 32, and 35, were arrested under the same act following separate raids by Greater Manchester Police (GMP) at 0500 GMT on Wednesday.

UK-wide investigation

All four men are being taken to London to be questioned by anti-terrorist detectives.

A police spokesman said the arrests were not connected with the death of Detective Constable Stephen Oake, who was fatally stabbed during a counter-terrorism operation in the city on 14 January.

I'm really shocked and of course I am very worried Nanda Maisuria - Hulme resident

Special Branch officers working with GMP's Tactical Aid Unit and Anti-Terrorist Branch officers carried out the raids.

They were assisted by officers from Scotland Yard.

Police said the arrests were part of the ongoing UK-wide investigations into terrorism.

The first three men were held after the raids, at Cooper House in Camelford Close and Thomas Court in the Hulme area of Manchester and Deal Street in Bury.

Chief Superintendent Tony Porter sought to reassure local communities that efforts were being made to "minimise risk" to the public.

'Extremist threat'

Mr Porter, head of community affairs for the force, said: "Manchester has been touched by terrorism before and is therefore no stranger to the implications of such extremism in its midst.

"Extremism and terrorism are facts of modern life.

"The police have the task of not only tackling this type of threat but, equally, those that aim to exploit the feelings of uncertainty and insecurity that such activities naturally create."

Mr Porter said police in Manchester had "the experience, expertise and commitment to deal with this threat".

Residents of Thomas Court in Hulme, expressed their surprise at the dawn raids on terrorist suspects.

Local shop owner Nanda Maisuria, 50, said: "I'm really shocked and of course I am very worried. I have been here for 30 years and have never had any problems."