Italian police have raided an alleged terrorist cell in Venice today, arresting three men and a young woman who were planning to travel to Syria.

The suspects were detained in the heart of historic Venice, in a series of raids conducted by police in the early morning.

All four of the suspects are from Kosovo, but hold Italian residence permits. After conducting surveillance on the group, police launched the raids after references to last week’s attack in London were made. In that attack, a man with no apparent direct links to the Islamic State or Al-Qaeda killed four people near British parliament.

Police were concerned the group may conduct a similar attack, possibly on one of many tourist attractions in Venice, which hosts around 20 million foreign tourists every year.