Police have confirmed they have received a complaint of alleged criminal damage to Manchester City's bus following the team's 1-0 Premier League defeat to Liverpool at Anfield on Sunday.
Merseyside Police on Wednesday appealed for further information over the incident.
"We have now received a report of an alleged criminal damage of the Manchester City team coach following the Liverpool and Manchester City game on Sunday, 16 October," the statement said.
"The incident of alleged damage to the windscreen was reported to us on Tuesday 18 October, and further enquires are ongoing."
It is not the first time there has been crowd trouble around games involving Liverpool and City at Anfield, with the rivalry between the two clubs intensifying in recent years as they have battled for supremacy.
Liverpool were fined in 2018 after fans attacked the City bus as it arrived at Anfield for a Champions League game.
City manager Pep Guardiola said coins were thrown at him from the stands during Sunday's fiery match, though he was not hit. Liverpool pledged life bans for those found guilty.
Liverpool also expressed their disappointment at chanting and graffiti by City fans on Sunday referencing the Heysel and Hillsborough stadium tragedies in the 1980s.
Liverpool manager Jurgen Klopp was charged with improper behaviour on Tuesday over his dismissal by referee Anthony Taylor towards the end of the fixture for taking protests against the match officials too far.
He could face a touchline ban if found guilty.