Italian police are hunting a gang of armed robbers who blocked a motorway with burning vehicles and used a digger to rip open a security van “like a can of tuna” to steal €2.3 million (£2.1 million) in cash.

The four men, who were masked, fired shots from automatic weapons to intimidate the security guards inside the van.

The heist happened on a highway near the city of Bari in the southern region of Puglia.

The gang blocked the path of the security van by driving two trucks onto the motorway and setting them on fire.

They then used a one-armed digger to gouge open the security van, making off with the €2.3 million.

“They literally tore open the rear of the van, like it was a can of tuna,” one Italian newspaper reported, citing police officials.

They escaped in two high-powered cars. The three guards in the security van were badly shaken but unhurt.

The cash, pension money for postal office workers, was being transported to a regional office when the ambush took place on Wednesday.

Traffic was blocked on the highway for several hours as police investigated the raid and the emergency services removed the burning vehicles.

Such well-planned attacks on security vans have happened in the past.