Violent clashes between rival Mexican criminal groups – and their alleged allies in the security forces – are escalating ahead of mid-term elections in June, triggering a string of political assassinations and the forced displacement of thousands.

State and federal security forces have actively colluded with – and even fought alongside – the warring factions, according to local civilians, civil society activists and gunmen from various factions.

But as well as engaging in pitched gun battles, criminal factions are also confronting each other on the electoral field.

"All the [criminal] groups are trying to make gains right now," said a Michoacán political consultant with first-hand knowledge of how arrangements are brokered between organized crime and political candidates.