Moscow (AFP)

Four days after the nuclear explosion that killed at least five people on a base in the Far North, the Russian authorities acknowledged Monday that the accident was linked to tests of "new weapons", promising to lead them "until end".

US experts have estimated that the accident could be related to tests of the cruise missile "Bourevestnik", one of the new weapons "invincible" praised by President Vladimir Putin earlier this year.

Without being so specific, the Russian nuclear agency assured Monday, celebrating the memory of the five members of its staff killed, want "continue work on new types of weapons, which will in any case be continued to the end ".

"We will fulfill the duties entrusted to us by our homeland, and its security will be fully assured," Rosatom boss Alexei Likhachev was quoted by Russian news agencies as saying.

The army had previously announced the death of two "specialists", without it being known whether they are included in the five deaths mentioned by the Russian nuclear agency.

Three other people were injured in the accident Thursday, victims of burns, according to Rosatom.

According to the nuclear agency, its specialists provided engineering and technical support for the "source of isotopic energy" of the missile engine that caused the explosion, which occurred on a "platform". "maritime" and who threw several employees into the sea.

Immediately after the accident, the Ministry of Defense had only stated that the facts had occurred during the testing of a "liquid propellant rocket engine", but did not describe the accident as involving nuclear fuel.

He had then assured that "there was no radioactive contamination", but the town hall of a town near the base said to have "recorded a brief increase in radioactivity" before withdrawing its publication.

- "Unique tests" -

The Russian president had caused a sensation last year and early 2019 by presenting the new generation of missiles developed by his country, "invincible", "undetectable" or "hypersonic". He has threatened to deploy these new weapons to target "decision centers" in Western countries.

Experts have linked Thursday's accident to the tests of one of these new weapons: the "Bourevestnik" ("storm bird" in Russian), nuclear-powered missile unveiled with great pomp by Vladimir Putin in February, but not still to the point according to the specialists. With "unlimited scope" according to the president, he would be able to overcome almost all interception systems.

The base of the Thursday crash, which opened in 1954 and specializes in missile testing of the Russian fleet, including ballistic missiles, is located near the village of Nionoska in the Far North.

The closed city of Sarov, home to the main Russian nuclear research center, Sunday declared a day of mourning and the five killed specialists will be posthumously awarded after their funeral on Monday.

"They have taken a double responsibility: in the development of unique technologies and equipment and taking the physical risk of performing unique tests," said Sergei Kirienko, a member of the presidential administration and former boss, at the ceremony. Rosatom, saluting "real heroes".

Known as "Arzamas-16" during the Cold War, the center of Sarov is at the origin of the first nuclear weapons of the Soviet Union.

At the beginning of July, 14 Russian army officers were killed in the burning of a nuclear submarine in the Barents Sea, under circumstances in which the Russian authorities largely remained silent, in the name of "secret State ". The fire could be controlled before touching the submersible nuclear reactor, according to the Ministry of Defense.

© 2019 AFP