MARIGNANE, France (AFP) — The co-pilot of the doomed Germanwings flight appears to have “deliberately” crashed the plane after locking his captain out of the cockpit, French officials said yesterday, in revelations that sparked global shock.

In a chilling account of the final minutes of Germanwings Flight 4U 9525, lead prosecutor Brice Robin said 28-year-old German Andreas Lubitz initiated the plane’s descent while alone at the controls.

Lubitz appeared to “show a desire to want to destroy” the plane, Robin told reporters after his team analysed the Airbus’ cockpit flight recorder.

However, Lubitz is not believed to be part of a terrorist plot, officials said.

In an initial reaction, German Chancellor Angela Merkel said the findings added an “absolutely unimaginable dimension” to the tragedy in which 150 people were killed, mostly Germans and Spanish.

Prime Minister Mariano Rajoy of Spain said he was “deeply shaken” by the news and sent his “heartfelt affection” to the victims’ families, dozens of whom had arrived near the crash site.

The passengers were killed “instantly” by the crash and were probably unaware of the impending disaster until the “very last moment”, the French prosecutor said.

“The screams are heard only in the last instants before the impact.”

“The co-pilot was alone at the controls,” he said. “[He] deliberately refused to open the door of the cockpit to the pilot.”

The pilot, believed to have gone to the toilet, made increasingly furious attempts to re-enter the cockpit, banging on the door, the recordings appear to show.

The co-pilot’s motive remains a mystery, but investigators have all but ruled out terrorism.

“At this moment, there is no indication that this is an act of terrorism,” Robin said.

A “stunned” Lufthansa Chief Executive Carsten Spohr said: “In our worst nightmares we could not have imagined that this kind of tragedy could happen to us here at the company.”

He added no security “system in the world” could have prevented the co-pilot’s actions.

Lubitz had passed all psychological tests required for training and underwent regular physical examinations, said the CEO.

In the first industry response to the disaster, low-cost carrier Norwegian Air Shuttle said it would require two people in the cockpit at all times.

Meanwhile, families and friends of victims gathered near the remote mountainous crash site area, where locals have opened their doors in a show of solidarity with the grieving relatives.

“We’re all pitching in of course. There’s no such thing as nationality, no such thing as religion,” said one local volunteer, Charles Lanta.