Wreckage from the Russian jet that crashed Sunday in the Black Sea killing 92 people has been found, the Russian officials Defense Ministry said Monday.

Pilot error or a technical fault — but not terrorism — were likely to have caused the crash, Russian Transport Minister Maxim Sokolov said in a statement.

Divers located several fragments of the plane Monday afternoon about one mile from the shore and 82 feet under the sea, the Emergency Situations Ministry said in a statement. the statement said. It said Some of the debris was recovered, and divers were going back into the water to search for more.

Finding the jet’s flight recorders may be difficult because the devices lack underwater locator beacons that are common in more modern planes.

Everyone aboard the Russian military’s Tu-154 plane are thought to have died when the jet crashed two minutes after takeoff Sunday from the southern city of Sochi en route to Syria, the Associated Press said.

The nation held a day of mourning Monday for the victims. Flags flew at half-staff, and TV stations removed entertainment shows from their schedules, Reuters reported.

"This is a terrible tragedy and irreplaceable grief for the families of the victims," Sokolov said. "I express my deep condolences to the families and friends of the victims."

In all, some 45 ships and more than 3,500 rescue workers are involved in the search for remains and plane debris, the Russian Defense Ministry said. Searchers used helicopters, drones and submersibles to look for bodies and debris.

Rescue teams had recovered 11 bodies as well as fragments of bodies, Russian officials said. Those were flown to Moscow, where the remains will be identified.

The passengers included dozens of singers in Russia’s world-famous military choir, nine Russian journalists and a Russian doctor known for her charity work in war zones, the AP reported.

Officials downplayed speculation that a bomb or terrorism might have caused the crash. But several aviation experts noted factors that could suggest a terror attack, such as the crew’s failure to report any malfunction and the fact that plane debris was scattered over a wide area, the AP said.

“Possible malfunctions … certainly wouldn’t have prevented the crew from reporting them,” Vitaly Andreyev, a former senior Russian air traffic controller, told RIA Novosti.

The plane originated at Moscow’s military airport of Chkalovsky and stopped in Sochi for refueling before heading to Syria, where the choir was to perform a New Year's concert at a Russian military base. Despite the Syrian connection, Sokolov said the government sees no need to heighten security measures at Russian airports.

Some choir members did not go to Syria for personal reasons, the AP said. Soloist Vadim Ananyev stayed behind to help his wife with the children following the birth of their new baby.

“I have lost my friends and colleagues, all killed, all five soloists. I feel in complete disarray,” Ananyev told the AP. “It is such a shame. I have known these people for 30 years. I know their wives and children. I feel terrible for the children and for all that I have lost.”

Ananyev said he had received condolences from all over Russia and from abroad. “We were loved all over the world, never mind the political situation,” he said.

Mourners stopped by the Sochi Adler airport on Monday to light candles at the airport’s chapel and lay flowers at an improvised shrine that featured photos of the plane and of some victims.

The Tu-154 is a Soviet-built, three-engine airliner designed in the late 1960s, the AP reported. More than 1,000 have been built, and they have been used extensively in Russia and worldwide. The plane that crashed Sunday was built in 1983 and underwent factory check-ups and maintenance in 2014, the Defense Ministry said.

Tu-154 aircraft have been involved in a number of accidents in the past, including the April 2010 crash that killed Polish President Lech Kaczynski and his delegation, Agence France-Press said. The planes are no longer used by commercial airlines in Russia.