Since the dreadful attack on Manchester Arena, a huge operation has been launched to hunt down those behind it.

Suicide bomber Salman Abedi was at the centre but authorities seem sure he did not act alone.

There have been a total of 16 arrests in the past week and 14 men remain in custody.

The investigation included a raid at an address in Chester - which has not been revealed by police - early on Monday morning (May 29).

Cheshire Constabulary said no arrests were made.

The operation now stretches from in and around Manchester to Liverpool, the Midlands and even Shoreham-by-Sea in Sussex.

Greater Manchester Police are leading it, with support from forces across the country.

Alongside Counter Terrorism Policing North West, they are trying to uncover a network who helped plan and carry out the attack which saw 22 people killed.

GMP chief constable Ian Hopkins said: “The whole team are working round the clock.

"We have around 1,000 people involved in the investigation alone. In addition there are hundreds of officers and staff from Greater Manchester Police and other forces involved in the security around Greater Manchester.

“In the past five days we have gathered significant information about Abedi, his associates, his finances, the places he had been, how the device was built and the wider conspiracy.

“As a result of the arrests and searches which have taken place we now have many further lines of enquiry. We already have more than 1,500 actions we are pursuing.

“This is still a live investigation which is not slowing down. Our priorities are to understand the run up to this terrible event and to understand if more people were involved in planning this attack.”

Time Line

Timeline of Manchester attack investigation arrests

  1. May 23

    A 24-year-old man arrested in Whalley Range, Manchester. He remains in custody.

  2. May 24

    Three men aged 24, 21 and 18 arrested in Fallowfield, Manchester. They each remain in custody.

  3. May 24

    A 33-year-old man arrested in Wigan. He remains in custody.

  4. May 24

    A 22-year-old man arrested in Nuneaton. He remains in custody.

  5. May 24

    A 34-year-old woman arrested in Blackley, Manchester. She has since been released without charge.

  6. May 25

    A 38-year-old man arrested in Blackley, Manchester. He remains in custody.

  7. May 25

    A 16-year-old boy arrested in Withington, Manchester. He has since been released without charge.

  8. May 25

    A 30-year-old man arrested in Moss Side, Manchester. He remains in custody.

  9. May 26

    A 44-year-old man arrested in Rusholme, Manchester. He remains in custody.

  10. May 27

    Two men aged 22 and 20 arrested in Cheetham Hill, Manchester. They both remain in custody.

  11. May 28

    A 25-year-old man arrested in Old Trafford, Manchester. He remains in custody.

  12. May 28

    A 19-year-old man arrested in Gorton, Manchester. He remains in custody.

  13. May 29

    A 23-year-old man arrested in Shoreham-by-Sea, Sussex. He remains in custody.

  14. May 29

    Raid on an address in Chester. No arrests made.

People have seen an increased police presence in Chester city centre in recent days.

A similar raid to what took place in Chester was simultaneously carried out in Whalley Range.

Cheshire Constabulary said there was 'no direct threat to the public' in the county.

Detective Superintendent Aaron Duggan said: “This morning’s activity will understandably cause concern within the local community and I want to reassure residents that as part of the on-going investigation there will be an increased police presence in the area.

"Officers will be visible in Chester over the next few days providing reassurance and if any members of the community have any concerns then I would encourage you to speak to local officers.

“We will continue to work closely with our communities by carrying out patrols over the coming weeks and addressing any concerns they may have."

To report any suspicious behaviour contact the Anti-Terror hotline on 0800 789321 or in an emergency call 999.