"FIFA is deeply saddened by the deaths of several football fans in Calabar and offer our deepest condolences to family and friends of the victims", the world football body wrote on its Twitter handle on Friday.
The British High Commission in Nigeria said: "Our deepest sympathy for the loss of lives in Calabar during a Europa League football match between Manchester United and Anderlecht".
A survivor, in an interview with journalists according to the report on Channels Television, revealed that a transformer near the viewing centre located in the Inyang-Esu area of Calabar Municipal Local Government Area, exploded during the match.
"I heard a deafening bang".More news: Divyanka Tripathi shares her opinion on Sonu Nigam's Azaan Tweet
Police confirmed at least seven are dead and 10 more were are critically injured. Come to think of it, I have DStv at home but I enjoy watching matches at viewing centres.
"It was a frightful sight to behold".
Local Ukeme Joseph said he believed at least 20 people had died after the wire collapsed onto the Calabar viewing centre.
Around 80 supporters are reported to have been crammed inside the building.More news: New Poll Could Impact Marijuana Legalization In PA
Gov. Ben Ayade said: "The incident marks a dark chapter in the life of the state where the precious lives of football lovers have been lost".
United netted an extra time victor through Marcus Rashford, in between scoring two disallowed goals.
Also, the country's President Muhammadu Buhari on Friday expressed shock over the event, in a statement issued by his Senior Special Assistant on Media and Publicity, Garba Shehu.
Also, Manchester United have sent a condolence message to families of the victims.More news: Some US companies that have left or scaled back in Venezuela
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