The four members of the rock band Viola Beach and their manager were killed when their car crashed in Sweden early on Saturday morning, according to Britain's Foreign Office, citing reports in Swedish media.
Police confirmed the men found dead in a canal in Sodertalje near Stockholm were aged between 20 and 35 and were from Britain. Their car plunged 26 meters from a motorway into the canal, apparently going through the barries on a bridge that was up.
"For some reason, this car went through the barriers and actually went under the bridge and into the Sodertalje canal," a police spokesman said.
"The investigation so far shows no problem with the barrier. It was down and the lights were on. Other cars had stopped by the barrier."
The band, which came from Warrington, in northern England, was in the Friday night line-up at the "Where's the Music" festival in Norrkoping, south of Stockholm.
"We can confirm that five British nationals died in a car accident in Sweden," a Foreign Office spokesman said. "We are in contact with local authorities and are supporting the families at this very difficult time."
Viola Beach recently recorded a session for the BBC and was due to play at the SXSW music festival in Austin, Texas, next month, according to their Facebook page.