Muhamadi has links to the West Midlands area, police said, and was last seen at about 21:00 BST on 18 May in Birmingham city centre after travelling by train to the city.
He then travelled in a taxi towards Coventry Road and the Small Heath Park area, with those who saw him or know his current location asked to contact police.
The two men both worked in convenience stores in Doncaster and lived in a flat in the Hexthorpe area.
The trial heard that Muhamadi was taken into the care of social services in Bradford after entering the UK as an unaccompanied asylum seeker.
He had made a claim for asylum in 2021 at the age of 16 and was granted leave to remain in the UK in 2022, to be reviewed in 2027.
In 2023, he moved to Doncaster and began working “long shifts” in a shop.
After the verdicts were delivered, Judge Sarah Wright thanked jurors, saying: “You should not underestimate the task you have undertaken, a great public duty, which you carried out with great care and diligence.”
According to South Yorkshire Police, the investigation into the two defendants began in August 2024, after one of the victims said she had been abused by a man she knew as “Karo”, and had been in contact with another man she knew as “Jack”.
It later transpired that “Karo” was Harwe and “Jack” was Muhamadi.
Discussing the search for the defendant, Assistant Chief Constable Hayley Barnett said: “We are wholly focussed on finding Muhamadi and ensuring his faces the consequences of his actions.
“We believe he is still in the country, but if he is found abroad we will seek the government’s help in doing everything we can to extradite him.
“We will not stop until we find him and we will ensure these young girls get the justice they deserve.”