Bah has deposited his buyout clause to the RFEF, so leaving him free from his Valladolid contract today.
The teenage defender is understood to be joining City and will be signing with the club's umbrella company, City Football Group.
Bah and his agent informed Valladolid yesterday of their intentions to leave, with his buyout clause matched today.
Valladolid management are furious and are convinced City are behind Bah's decision.
In a statement, the LaLiga minnows declared:
"Abdulai Juma Bah and his agent informed Real Valladolid yesterday afternoon of their intention to unilaterally break the contract that binds both parties. Previously, yesterday afternoon, Manchester City sent a statement asking Real Valladolid to open negotiations for the player for a possible permanent transfer.
"Today, the Sierra Leonean has decided not to show up at his workplace for morning training. For all these reasons, the Club holds the player responsible for the breach of his contractual commitments, and has asked its legal department to initiate disciplinary action in this regard.
"The Club considers that Manchester City, a member of the City Football Group, is behind the Player's decision, and appears to have advised the player to take this route, which puts Real Valladolid in a defenceless position, after having recently rejected financial offers of a higher amount, especially since the player is in the protected legal period of his youth stage and, in recent days, had refused to sign the professional player's licence, since this would entail an automatic increase in his termination clause. The Club warned the three parties about this situation yesterday through different requests, warning them of the possible consequences of their actions.
"Juma Bah arrived at the Anexos last summer on loan from AIK Freetown. The loan contract with the Sierra Leonean club ended on June 30 of this season and included a clause for Real Valladolid to exercise a purchase option, a clause that the Blanquivioleta entity exercised on January 1 so that the central defender's federative rights would belong to Pucela under a new contract of longer duration, and with better conditions.
"The player's intention, supposedly supported and guided by Manchester City and his agent, has caused great disappointment and indignation within Real Valladolid, who welcomed Juma Bah with open arms and gave him the opportunity of a lifetime.
"The Royal Spanish Football Federation has just confirmed that the player has deposited the amount for the unilateral termination of the contract. In this regard, Real Valladolid reports that it reserves the right to resort to the appropriate legal and sporting jurisdictions to exercise its rights and defend its interests."