Blake, who was 17, was from the Limavady area.
Detective Chief Inspector Mark Gibson said: “Police received a report at around 9.35pm last night, Friday 2nd February, that a man in his 50s had been stabbed.
“Officers attended and while carrying out enquiries they located Blake who was also seriously injured with stab wounds in a nearby house.
“Blake was taken to hospital where he subsequently died from his injuries.
“The second injured man was taken to hospital, where he remains for treatment to injuries which are not believed to be life threatening at this time.
“Six males have now been arrested and are currently in police custody assisting with enquiries.”
Detective Chief Inspector Gibson continued: “We are at an early stage of this murder investigation and officers remain in the area conducting enquiries.
“We are appealing to witnesses or anyone with information to contact detectives on 101 quoting 1924 02/02/24. Information can also be provided to the independent charity Crimestoppers on 0800 555 111.
“You can also submit a report online using our non-emergency reporting form via http://www.psni.police.uk/makeareport/.”