The United Nations has named four British nationals -- two women and two men -- fighting for the Islamic State group in Iraq and Syria in a sanctions list released Tuesday. The four individuals, currently believed to be living in the ISIS-held Syrian city of Raqqa, will now have their assets frozen and face a travel ban.

This is the first time since 2006 -- when a British al Qaeda operative was added to the list -- that the U.K. government has submitted names of individuals to be sanctioned. As a result of the sanctions, those named in the list cannot travel through or to any country that is a member of the U.N., or keep their money in any U.N. member state.

“These sanctions are a powerful tool -- freezing an individual’s assets and imposing a global travel ban on them ... sends a clear deterrent message,” a spokesman for Prime Minister David Cameron reportedly said.

The four individuals sanctioned are Aqsa Mahmood, a 21-year-old “jihadi bride” accused of recruiting three London schoolgirls for ISIS; Nasser Muthana, 21, accused of appearing in several ISIS beheading videos; Sally-Anne Jones, a 46-year-old former rock musician dubbed the “punk jihadi” by sections of British media; and Omar Hussain, a 28-year-old former supermarket security guard.

“We will continue to consider whether more individuals should be subjected to the sanctions,” the government spokesman reportedly said.

Approximately 700 British nationals have travelled to Syria and Iraq to provide support to, or fight for, militant groups in the region, including ISIS. The most infamous among them is Mohammed Emwazi -- a former London resident dubbed “Jihadi John” -- who has appeared in at least seven execution videos released by ISIS, including one depicting the beheading of American journalist James Foley.