The interior ministers of the UK, Germany and France have vowed to help Tunisia fight terrorism, laying wreaths at the scene of the recent beach massacre. Authorities have made the first arrests related to the attack.
Tunisian Interior Minister Mohamed Najem Gharsalli announced that the suspects arrested on Monday were associated with the alleged "Islamic State" gunman who killed 38 people on Friday. Most of the victims in the attack on the beach resort were foreign tourists.
The gunman, identified as 23-year-old student Seifeddine Rezgui, was subsequently shot dead by police.
The security forces arrested "a significant number of people, from the network that was behind this terrorist criminal," Gharsalli said, speaking alongside the interior ministers of Britain, Germany and France.
"We will find all those involved, whether it was just logistical support or not," Gharsalli added, without providing more details.
The Western interior ministers visited the site of the massacre on Monday and paid tribute to the victims.
So far, 18 of the people killed in the attack have been confirmed as British nationals. However, the authorities in London expect that number to rise to "around 30," Prime Minister David Cameron's spokeswoman announced on Monday.
Britain's Home Secretary Theresa May described the attack as "a despicable act of cruelty."
"We are resolved... to defeat those who would do us harm, to defeat those who would undermine our freedom and democracy and to ensure that the terrorists do not win," she said, speaking from the Riu Imperial Marhaba hotel targeted by the shooter.
French Interior Minister Bernard Cazeneuve echoed May's words and said: "We will win this war."
"I want to express the absolute determination we have to reinforce our cooperation in the fight against terrorism," said Cazeneuve, adding that France would "ensure the development" of Tunisia's economy.
German Interior Minister Thomas de Maiziere also said that the four countries would work together against the terrorists.
"We came here to show solidarity with this young and still vulnerable democracy," de Maiziere said. "We are determined to show that freedom is stronger than terrorism."
'Intolerant of intolerance'
Friday's attack was the worst by a jihadi group in Tunisia's history, and claimed more British lives than any terror strike since the 2005 London bombings.
On Monday, British Prime Minister David Cameron called for "a response at home and abroad" to violent Islamic fundamentalism.
"We must be more intolerant of intolerance - rejecting anyone whose views condone the Islamist extremist narrative and create the conditions for it to flourish," he wrote in the "Daily Telegraph."
Speaking in parliament on Monday afternoon, Cameron announced a moment of silence next Friday in the victims' honor, on the one-week anniversary of the attack.
Some 600 British counterterrorism police members have been deployed to assist in the investigation of the attack. In addition, a British military plane would help with evacuation of the wounded tourists, officials said.
dj/msh (AFP, dpa, AP, Reuters)