It is reported Mancini stepped in after Balotelli went in too strongly on team-mate Scott Sinclair for the City boss' liking.
Balotelli is reported to have taken exception to Mancini's intervention, leading to the pair having to be pulled apart.
In the sequence of pictures, Mancini is seen striding towards Balotelli, pointing in an aggressive manner.
He is then seen to grab hold of Balotelli's orange bib in an apparent act of fury before the young striker is dragged away by a member of City's coaching staff.
A short time later, Balotelli is believed to have left the training ground at Carrington, on the outskirts of Manchester.
The Italian striker has put in some inept contributions for City this season, including against Manchester United last month when he was surprisingly preferred to Carlos Tevez.
Mancini responded to that display by warning Balotelli he risked wasting his considerable talent by failing to devote enough time to his career.
Balotelli has not played since, partly due to Mancini's own selection decisions but also a slight virus.
Although City have previously stated they will not sell the 22-year-old during the present transfer window, Thursday's development may well make the Blues think again should any club lodge a substantial enough bid.