700 Britons have travelled to Syria

British police reported on Thursday that more than 700 Britons are thought to have travelled to Syria, over half of which had already returned to the UK.

Scotland Yard's top counter-terrorism officer Mark Rowley added that “a significant proportion” were thought to have tried to join the Islamic State (IS).

IS and other terrorist groups are encouraging British citizens to travel to Syria to fight and train

"[IS] and other terrorist groups are trying to direct attacks in the UK; encouraging British citizens to travel to Syria to fight and train; and are seeking, through propaganda, to provoke individuals in the UK to carry out violent attacks here," Rowley said in a statement.

This news came a day after UK Prime Minister David Cameron announced that new legislation aimed against extremists radicalising young people will be unveiled in the Queen’s speech on 27 May.

Read more: Cameron to fast-track UK counter-terrorism measures

Rowley also warned that statistics revealed increasing numbers of women and teenagers becoming embroiled in extremism.

He said that potential attacks in domestic land could come from lone actors trying to carry out violent attacks or organised networks.

You may also enjoy reading:

Islamic State's second-in-command killed in Iraq air strike