A gang of criminals armed with Kalashnikovs stole four million euros (£3.4m) of pension funds from a convoy of armoured security vans on the island of Sardinia.

‌Dressed in military fatigues, the criminals forced the vehicles to a halt after using a stolen bin lorry to block a highway near the town of Sassari on Wednesday morning.

‌They then opened fire on the convoy, hitting one of the security guards in the leg amid a hail of bullets before prizing the van’s safes open with angle grinders and making off with the money.

The money was being transported to post offices when the heist took place at about 8am local time.

The gang’s tactics were likened to those previously employed by a criminal network from Italy’s southern town of Cerignola which has committed a string of high-profile robberies in recent decades.

Reports of the network’s methodical planning, which allegedly saw it scout out targets for months, and its use of high-powered getaway cars drew comparisons to the plot lines featured in the “Fast & Furious” film series.

Police launched a manhunt across the island for the perpetrators of Wednesday’s robbery, and later found a bag stuffed with explosives dumped on the side of the road.

Two getaway cars used were also discovered abandoned in the Sardinian countryside.

‌Eyewitnesses to the robbery described the gang as highly organised.

Gang was ‘perfectly organised’

‌“They didn’t speak to each other. They understood each other and were perfectly organised,” one motorist told the island’s La Nuova Sardegna newspaper.

Highway robberies are increasingly common in Sardinia with more than a dozen such heists carried out over the past decade.

Lorenzo Tramaglino, the head of a confederation representing private security guards, said their work was increasingly dangerous because of the uptick in crime.

Italy’s 60,000 security guards were not sufficiently protected or paid for the risk they are exposed to, he said. 

‌“It’s a slaughter out there. The assault methods are becoming more military and more dangerous. Tragedies will happen not just to security guards but people in the immediate vicinity,” he said.

Vans of the kind raided on Wednesday frequently carry up to six million euros and have no police escort, Mr Tramaglino added.