Emmanuel Macron has requested “international cooperation” in hunting down “France’s most wanted man” a day after his bloody escape as experts said “he will try to cross borders”.

French police have been given “unprecedented means” to locate and seize Mohamed Amra, 30, and a commando of accomplices who killed two prison officers on Wednesday as they freed him from a prison van at a motorway toll in Normandy, northern France. Three others are in a serious condition, one life-threatening.

Footage from surveillance cameras and witnesses shows the cold-blooded, military-style operation in which a black Peugeot rams the police van and another police vehicle, while a white Audi traps them from behind. Balaclava-clad men in black, who Le Parisien said were wearing flak jackets and wielding Kalashnikovs, then surround the vehicle, open fire and release the inmate.

Amra, nicknamed The Fly and The Smurf, is a dangerous repeat offender with 13 previous convictions. He faced various charges relating to drug trafficking and is believed to have ordered an assassination from his prison cell. He had attempted to saw his way through the bars of his prison cell three days ago and had been placed under higher surveillance as a result.

“We have put a lot of resources into finding the person who escaped and the gang who freed him in despicable conditions,” said Gérald Darmanin, interior minister.

“Unprecedented resources in terms of international cooperation and judicial police have been deployed at the request of the president,” he told RTL.

The interior ministry declined to confirm to The Telegraph whether this would include border checks. However, French security experts said there would inevitably be heightened controls at all ports.

“Mohamed Amra will try to cross borders”, said Gen Jacques Morel of the gendarmerie and former head of the Versailles search unit, adding that escape abroad is one of the most likely scenarios and is being taken very seriously by investigators.

“Given the preparation that went into this attack and the people he had around him, I think they would also have thought through his getaway. He had a fallback point, perhaps not very far from where it happened. He will try to cross borders, either to North Africa or to Spain”, Mr Morel told Francetvinfo.

The expert, however, said it would be a hugely complex task to track him down. “You know the problems with borders, it’s not that easy to control them. So the number one plan is to try to catch him before he flees abroad,”” Mr Morel said.

David Corona, a police profiler and former instructor in police negotiations, also said “international cooperation” meant border checks.

Philippe Brun MP for the Eure constituency where the attack took place, said: “I don’t think, as we speak, that they are in the immediate vicinity of our constituency. I even think that they are already a long way away as we speak.”

Prison guards ‘angry’ over conditions

Mr Darmanin, insisted investigators were “making a lot of progress”, adding on Wednesday that “more than 450 police and gendarmes” were mobilised “for the Eure department alone”.

There is “an enormous amount of…evidence that will enable us to carry out this identification work”, he added.

Shocked by the first murders among their number since 1992, penitentiary officers blocked dozens of prisons around France on Wednesday morning in support of their slain colleagues and to protest against a lack of means in dealing with increasingly violent inmates.

As they staged “dead prison day”, union leaders will meet justice minister Olivier Dupond-Moretti on Wednesday afternoon.

They are calling for “a drastic reduction in prisoner transfers by encouraging the use of videoconferencing for magistrates or their travel to establishments”, and “an overhaul and harmonisation of escort levels”.

The slain officers stood no chance in a shootout between “a simple Sig Sauer (handgun) versus opposed to weapons of war”, said Frédéric Liakhoff, FO-Justice unionist rep at Caen prison.

“Yesterday we were dumbfounded, but now we’re angry. Our colleagues are unanimous: we can’t go on like this, we need concrete measures and that’s what we’re waiting for from the justice ministry. We want measures to improve our safety and our working conditions”, said Erwan Saoudi of the FO Justice Paris union.

‘‘France at tipping point over drug trafficking threat’ ’ 

As the manhunt continued, the Macron administration was reeling from accusations it has failed to grasp the extent to which drug trafficking has “submerged” France.

A senatorial report released on Tuesday warned that the country had reached a “tipping point” in which “the rule of law” in certain areas had come under serious threat from the narco-industry, which officials say rakes in up to €6 billion per year in France and “employs” 240,000 people.

The government’s response so far has been “meagre” and “not up to the task”, warned the cross-party commission of inquiry, despite a high-profile, nationwide drugs “clean-up” operation launched two months ago.

The brutal assault and report on drugs comes less than a month before European elections in which Mr Macron’s candidate, Valerie Hayer is trailing the hard-Right National Rally led by Jordan Bardella.

In a visit to the Fresnes prison outside Paris on Wednesday morning, François-Xavier Bellamy, the head of the Republicans list for the European elections expressed “his solidarity with all prison staff”.

“Today, the state is losing the war”, he said.

“The warnings have been repeated all too often”, he added, stressing “the urgent need to give our police and prison forces the resources they need to carry out their duties”.