A Prison Service source suggested the prison van ambush would probably involve one of the escapees having access to a smuggled mobile phone.
A phone call could then be made or a text sent to let the armed gang know which prison van they were in and so which vehicle to target, among the number of vans making their way from jail to Manchester Crown Court.
More top news
A Royal Marine from Northern Ireland who built explosives for an Irish republican paramilitary group had 43 hides, a court has heard.
A gay man has spoken of pain he suffered as a young boy when doctors gave him chemicals and electric shocks in attempt to 'cure' him.
Showers in the north tonight, elsewhere mostly dry.