Four British jihadis who have travelled to Syria to join Islamic State have been hit with UN sanctions.
They are: Omar Hussain from High Wycombe, Nasser Muthana from Cardiff, Aqsa Mahmood from Glasgow and Sally Jones from Chatham, in Kent.
Under the UN's al Qaeda sanctions regime, the jihadists will face a global asset freeze and travel ban.
It means if they try to cross into another country they are likely to be arrested on the spot.
Jones went to Syria in 2013 with husband Junaid Hussain, who was killed in a US airstrike in August.
She uses social media as a recruitment tool to get women to join IS.
After the announcement a response was posted on a Twitter account believed to belong to Jones.
"Just found out from a article that David Cameron has put me on a UN Sanctions list as i lol @ England for giving me a travel ban :)," it said.
"England i came here to fight you fisabilillah [for the sake of Allah] & i will until my last breath."
Mahmood also went to Syria two years ago, and is believed to be a key figure in the al Khanssaa brigade, a female brigade in Raqqa which was established by the militants to enforce Sharia law.
Hussain, who is also known as Abu-Said al Britani, travelled to the country last year and also uses social media for recruiting fighters.
Muthana, who has been in Syria since 2013, has appeared in IS propaganda and recruitment videos.
He has used social media posts to threaten the UK.
No 10 hopes the sanctions will act as a deterrent to others considering following the 700 Britons who have already made the journey to Syria and Iraq to join IS.
A Government spokeswoman said: "The Prime Minister has been absolutely clear that we will do all we can to stop British citizens from going to fight for ISIL (another name for IS) and that foreign fighters should face consequences for their actions.
"As well as the domestic measures we have introduced, such as the power to seize passports, these sanctions are a powerful tool - freezing an individual's assets and imposing a global travel ban on them.
"It also sends a clear deterrent message to those thinking of going to fight for ISIL."
It is the first time since 2006 that the Government has sought to subject British nationals to the UN sanctions regime.
Previously it has been used against people linked to al Qaeda.
Dossiers of evidence were provided to show they were "participating in the financing, planning, facilitating, preparing or perpetrating of acts or activities" related to IS.
One of the five names submitted by the UK to the UN is still to be approved, and more names are expected to be put forward.