Detectives investigating a self-styled Muslim patrol gang made two more arrests, Scotland Yard said.
Men aged 25 and 29 are in custody, bringing the number held so far in the investigation to four, a spokesman said.
Officers are investigating a string of incidents in east London over the weekend of January 12 and 13 where the group harassed members of the public.
A video posted on YouTube showed the gang hurling homophobic abuse at one man, whom the police have urged to come forward.
In the film, titled "Muslim vigilantes in London harass and taunt gay male", they are heard to shout "get out of here you fag... don't stay around here any more".
In a second video, also posted online, men from the gang in Whitechapel tell another man "no drink in this area, it's a Muslim area" before ordering him to pour away his alcohol.
Detective chief inspector Wendy Morgan from Tower Hamlets borough said: "The Met takes such homophobic behaviour very seriously.
"This man is a crucial witness in the investigation and we would encourage him and anyone else with information relating to this incident to make contact in confidence as soon as possible."
Additional police patrols are being mounted across east London to reassure the public.
A 22-year-old man was arrested in Acton, west London on Sunday, and a 19-year-old man was held after going to an east London police station on Monday. They have been bailed to return to police on March 12 and March 11 respectively.
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