Over 30 people were reportedly electrocuted by a high tension cable that fell on the viewing centre in Calabar, the Cross River State capital, on Thursday.
According to Channels TV, the football fans were at the centre to watch the UEFA Europa League quarter-final match between Manchester United and Anderlecht on satellite television.
Manchester United won the match 3-2 aggregate, with Marcus Rashford netting the winner in the 107th minute.
Channels TV correspondent in Calabar reported that the live electricity cable broke from its mooring and fell on the viewers.
One man tweeting from Calabar provided the specific location of the accident:
Uwemedimo Ekeng @Eb_Ekeng
High tension drops, kills over 30 who were watching MANUTD Vs Anderlecht in a building along Akpandem Street, Atimbo calabar.