LONDON: The Football Association will investigate reports of crowd trouble among West Ham United supporters at Saturday's Premier League game against Watford.

"We have been in touch with the club and the relevant authorities and there will be more conversations on Monday," a spokesman said on Sunday.

West Ham, playing only their second league game at the former Olympic Stadium, now known as the London Stadium, issued a statement saying they would ban for life anyone involved in the trouble.

They lost the match 4-2 after leading 2-0.