New footage emerges of Tunisia terror attack as minute's silence announced

Tunisian interior minister Mohamed Gharsalli said a "significant number" of individuals allegedly linked to Seifeddine Rezgui have been detained.

David Cameron today announced there will be a nationwide minute's silence at midday on Friday, while Home Secretary Theresa May condemned the "despicable act of cruelty" after she visited the scene of the attacks.

A total of 38 people, including up to 30 Britons, died after 23-year-old student Rezgui opened fire in the resort of Sousse on Friday.

The self-proclaimed Islamic State - also known as Isil - later claimed responsibility.

The number of British victims confirmed dead reached 18 today but it is expected to rise to around 30 in the coming days.

Announcing the minute's silence, Mr Cameron told MPs: "I know the whole country will want to share in a moment of remembrance."

The Prime Minister, who earlier described the "existential threat" posed by IS as "the struggle of our generation", told the Commons: "We will not give up our way of life or cower in the face of terrorism."

He added: "This is not the war between Islam and the West which Isil want people to believe - it is a generational struggle between a minority of extremists who want hatred to flourish and the rest of us who want freedom to prosper - together we will prevail."

He said Britons were not being advised to stay away from Tunisia's coastal resorts despite the bloody events at Sousse, while he also disclosed that a major exercise will take place in London this week to ensure the UK is prepared to deal with terrorism.

Home Secretary Theresa May travelled to Tunisia today. She laid flowers and observed a period of silence at the scene of the attack.

Speaking later at a press conference, she said: "How could a place of such beauty, of relaxation and happiness, be turned into such a scene of brutality and destruction?"

She said she had heard "horror stories" of those caught up in the attack and accounts of "great bravery", including Mathew James, who was hit in the hip, chest and pelvis as he shielded wife-to-be Saera Wilson from gunfire.

Mrs May held talks with Tunisian, German, French and Belgian ministers on addressing the threat posed by IS.

"We are very clear that the terrorists will not win. We will be united in working together to defeat them, but united also in working to defend our values," she said.

Downing Street said all British nationals injured would be returned within the next 24 hours.

Four people needing treatment are being flown back to the UK on board an RAF C17 plane with "medevac" teams experienced at bringing injured service personnel back from operations overseas. The aircraft left the Brize Norton base in Oxfordshire at lunchtime.

The Prime Minister said the Government is working "as fast as we can" to get information to families still waiting in anguish for news of missing loved ones three days after the attack.

His spokeswoman said that delays in identifying the dead are due in part to the fact that the holidaymakers may not have been carrying identification at the time of the attack.

In two cases where authorities "feared the worst", individuals thought to have possibly been victims of the gunman were this morning tracked down alive and well in the UK, she said.

Mr Cameron's spokeswoman said that UK authorities were "working closely" with relatives of those killed to offer help with the repatriation of the bodies of their loved ones, and that some were expected to be brought home this week.

Holiday firms Thomson and First Choice issued a statement saying they are "aware that some families continue to wait for news of their loved ones".

It added: "We would like to reassure those in this position that we are doing everything we can to provide information as soon as we are able to do so."

Former navy chief Lord West said Britain must step up the "propaganda war" against Islamic State, also known as Isil or Isis, who he said were "running rings around us in terms of the social media they are putting out".

He also suggested the UK should consider joining the US in air strikes on IS targets in Syria and the West should consider working with Syrian president Bashar al-Assad.

Scotland Yard has said more than 600 officers are involved in what is its largest counter-terrorism operation since the 7/7 bombings.

London mayor Boris Johnson said: "Our thoughts are with the victims and their families. We don't at the moment think there is any read-across with security in London.

"Clearly it is also very poignant that this should happen just at the moment that we are preparing next week to memorialise 7/7."