Police have arrested a 19-year-old man in West London under the Terrorism Act.

The arrest is the second to have taken place yesterday, with another 20-year-old man arrested in South West London. Both arrests are said to be ‘Syria related’.

The men were arrested under Section 41 of the Terrorism Act which allows suspects to be detained for up to 48 hours without charge if they are suspected of terrorism.

London Police gave no details other than the Syria link to the arrests, and that officers are conducting searches in South West, and West London addresses.

It was claimed in 2018 that the UK government doesn’t know the whereabouts of potentially hundreds of fighters who left Britain to fight for ISIS, and who may have returned. It is estimated that around half of those fighters returned to Britain, but the location of the others are not known by security services.

Security Minister Ben Wallace said at the time “maybe some of them [are] trying to get back to us here, but there’s a significant number that at the moment it is hard to actually tie down exactly where they are”.

Home Secretary Sajid Javid recently imposed new laws that allow for people travelling to Syria or other known off-limit areas without a viable reason, such as journalism or the funeral of a relative, to be jailed for up to 10 years on their return.

There are believed to be around 900 Britons who left the country to fight for ISIS, with around one fifth reportedly killed and 40-per-cent returning to the UK. Of those who returned, only 10-per-cent have been prosecuted.

The arrests come in the wake of a series of attacks in Sri Lanka in which Islamic Terrorists murdered 359 people in a series of coordinated attacks at churches and hotels. It is reported that one of the bombers — who came from a wealthy and successful family — studied in the UK.