The Russian plane, that crashed in the Sinai Peninsula in Egypt on Saturday, killing 224 people, had passed a safety review carried out by the Irish Aviation Authority (IAA) earlier this year.

The airplane, registered in the Republic of Ireland, had just left Sharm el-Sheikh and was on its way to St Petersburg, in Russia. Inquiries into the cause of the crash have not yet been conclusive.

The Russian airline, Kogalymavia, has blamed “external activity” for the crash. However, on Monday, Reuters reported that the plane was not struck from the outside and the pilot did not make a distress call before it disappeared from radar. This information came from source in the committee analyzing the black box records. No other information was given from the preliminary examination.

Alexander Smirnov, Deputy General Director of Kogalymavia, said only a "technical or physical action" could have caused the aircraft to break up in the air.

Speaking at a press conference in Moscow he said, “The plane was in excellent condition.

"We rule out a technical fault and any mistake by the crew."

Irish inspectors from the Republic of Ireland's Air Accident Investigation Unit and an expert from the IAA are expected to travel to Egypt to help with the investigation into the cause of the crash.

All 217 passengers, including 17 children, and seven crew died in the crash. The recovered bodies are currently being repatriated.

The aircraft disappeared from radar screens 23 minutes after take-off at an altitude of 31,000 feet (9,400 meters), Egypt's Civil Aviation Ministry said.

According to FlightRadar24, an authoritative Sweden-based flight tracking service, the aircraft was descending rapidly when the signal to air traffic control was lost.

The Airbus A-321 was registered in Ireland through a leasing company but was operated by Kogalymavia.

On Monday the IAA told the BBC the airplane's certifications "were satisfactory" on its last review. They added that the operation of the aircraft, including monthly checks was the Russian airline’s responsibility under International Civil Aviation Organisation rules.

Officials from Russia had said the plane had mostly likely broken up mid-air but could not yet say what caused this.

The first bodies recovered from the wreckage arrived home at St Petersburg’s Pulkovo Airport greeted by piles of flowers left by a grieving public. A second government plane was set to leave Cairo on Monday.

Russia's Metrojet says crash was caused by outside force, not a technical issue w/ the plane

— Mashable (@mashable) November 2, 2015
Russia’s President Vladimir Putin declared Sunday a national day of mourning.

He said, “Without any doubt everything should be done so that an objective picture of what happened is created, so that we know what happened."

An Egyptian militant group, affiliated with Islamic State, had said on Saturday that they were responsible for bringing down the plane “in response to Russian air strikes that killed hundreds of Muslims on Syrian land."

Russia's transport minister dismissed the claim and said it "can't be considered accurate.”

When asked whether this was a terrorist attack Putin’s spokesperson Dmitry Peskov said no theory could be ruled out.