Published: 17:52 EST, 15 December 2015 | Updated: 02:13 EST, 16 December 2015
Police in Sweden are investigating chilling letters posted through letterboxes across the country threatening to behead people unless they convert to Islam.
The notes, which are signed ISIS and carry the terrorist organisation's flag, threaten to decapitate 'non-believers' unless they become a Muslim or pay a religious tax.
They have been distributed among several cities including Stockholm and warn 'the police will not save you from being murdered'.