A third man has been arrested in connection with the murder of a 23-year-old during riots in Birmingham.
Residents repair their homes after a night of rioting
Two men, aged 22 and 25, were arrested on suspicion of murder on Thursday after Isaiah Young-Sam was stabbed in Carlyle Road, Lozells, last Saturday.
West Midlands Police said "excellent progress" was being made in the inquiry and further arrests were expected.
The rioting in the Lozells area of the city involved youths from the black and Asian communities.
It was said to have been sparked by a claim that a black girl of 14 had been raped.
Det Ch Supt John Jones, told a news conference in Birmingham on Friday officers were confident of bringing Mr Young-Sam's killers to justice.
"Two men are in custody and a third man has also been arrested, "he said.
"Evidence has come forward to suggest up to 12 men were involved and we do anticipate further arrests."
The third man is in his early 20s, police said.
Mr Young-Sam, his brother and two friends had been to watch a film at a cinema on Broad Street in Birmingham city centre before catching a bus and walking the short distance home along Carlyle Road.
He was just near his home when he was attacked - police said the ethnicity of the attackers and their motive were unclear.
No complaint received
Police said he was an innocent victim and not involved in the rioting. One of his friends was also stabbed in the back.
Thirty-five other people were injured in the violence last weekend.
Another man was shot dead on Sunday near the scene of further disturbances.
Two men arrested over the shooting in the Newtown area have since been released without charge.
Detectives said that forensic experts had been to the location of the alleged attack on the girl in the Lozells area but no formal complaint had been received.
Officers have so far found no evidence of an attack or identified the 14-year-old alleged victim.