West Ham and Charlton have announced that Tuesday's Carling Cup matches, against Aldershot and Reading respectively, have been postponed after a request from the police due to ongoing riots in London.
Violent scenes have blighted the capital for the last three days, after the fatal shooting of Tottenham resident Mark Duggan last Thursday prompted rioting and looting in the area at the weekend.
The disturbances, which have since spread to other parts of London and also Birmingham, have thrown many of this week's sporting fixtures into doubt with West Ham and Charlton's matches the first two to be called off.
A statement on West Ham's official website said: "West Ham United have been asked by the police to postpone the Carling Cup first-round tie with Aldershot Town tomorrow night.
"The club were contacted this evening and told that all major public events in London were to be arranged because of the need to focus police resources elsewere.
"Whilst neither the club or police anticipate any issues around the game itself, the club has to comply with the police request.
"No date has yet been set for the rearranged match, but the club will be in contact with the Football League and Aldershot."
Addicks chief executive Stephen Kavanagh confirmed the Charlton match at The Valley has been postponed on the club's official website.
He said: "We've been monitoring the situation as it's been developing all evening and have been in constant contact with the police.
"Clearly the most important factor is people's safety. The police have told us they believe the match should be postponed on safety grounds, and obviously we have taken that advice."
Crystal Palace's home clash with Crawley Town and Bristol City's meeting with Swindon have also been postponed, along with England's friendly international against Holland.