Up to 30 Manchester United fans in Nigeria are feared to have been electrocuted while watching the club's Europa League clash on Thursday night.
Witnesses have described how they saw a flash of light from a transformer which sent fans scurrying, packing them together before a "high tension" cable fell on them.
The incident occurred at a viewing centre in the city of Calabar.
As the club and the UK High Commission in Nigeria offered their condolences on Friday, local authorities have described the disaster as a horrifying tragedy.
Local media reported at least 30 fans died after gathering to watch the match against Anderlecht.
Twenty eight of the victims died on the spot while two more died in the hospital and about 50 others were injured, Today reported.
However, police had confirmed only seven deaths while 11 more were being treated in local hospitals, one of them in intensive care, the BBC reported.
Local media said a nearby transformer exploded twice during the match - and the second time the high tension wire snapped and dropped on to the viewing centre made of zinc.
Those standing closer to the door are said to have escaped.
One witness told local television how the disaster occurred. "I was sitting at the front seats when I saw the reflection form the transformer," he said.
"I was the first person to run outside. Everybody saw the reflection of the light from the transformer. Everybody was running to go out from the door. As they were running, everybody was jam-packing themselves. Because the high tension (cable) fall on top, (it) contacted everybody there." Police reportedly said: "Around 10 pm we were called that an incident that has happened so immediately our men went there. "According to the information we gathered the high tension [electric] cable that was very close to the viewing centre fell on the building."