Azerbaijan began a national day of mourning on Thursday after a passenger jet from the flag carrier crashed in western Kazakhstan on Christmas Day, killing 38 of the 67 people onboard.

The Embraer 190 aircraft was supposed to fly northwest from the Azerbaijani capital Baku to the city of Grozny in Chechnya in southern Russia, but instead diverted far off course across the Caspian Sea. It crashed Wednesday near the city of Aktau in Kazakhstan.

Azerbaijan Airlines reported that 67 people were on board the jet — 62 passengers and five crew members.

Kazakh Deputy Prime Minister Kanat Bozumbayev told Russia’s Interfax news agency that 38 people had been killed, while the Kazakh emergency situations ministry reported “29 survivors, including three children, have been hospitalised”.

Azerbaijani President Ilham Aliyev declared on Thursday a day of mourning and cancelled a planned visit to Russia for an informal summit of the Commonwealth of Independent States (CIS), a grouping of former Soviet nations.

Aliyev’s office said the president “ordered the prompt initiation of urgent measures to investigate the causes of the disaster”.

“I extend my condolences to the families of those who lost their lives in the crash … and wish a speedy recovery to the injured,” Aliyev said in a social media post.

The Flight Radar website showed the plane deviating from its normal route, crossing the Caspian Sea and then circling over the area where it eventually crashed near Aktau, an oil and gas hub on the eastern shore of the sea.

Azerbaijan state news agency Azertac reported that the aircraft’s black box, which records the flight data, has been recovered.

The Kazakh transport ministry said the plane was carrying 37 nationals from Azerbaijan, six from Kazakhstan, three from Kyrgyzstan and 16 from Russia.

Azerbaijan Airlines, the country’s flag carrier, said the plane “made an emergency landing” around three kilometres from Aktau.

The Kazakh emergency situations ministry said its staff put out a fire which broke out when the plane crashed.

It said 150 emergency workers were at the scene.

Kazakhstan said it had opened an investigation into the cause of the crash, which was not immediately clear.

Azerbaijan Airlines initially said the plane flew through a flock of birds before withdrawing the statement.

“We cannot disclose any investigation results at this time,” the office of Azerbaijan’s prosecutor general said in a statement.

“All possible scenarios are being examined, and the necessary expert analyses are underway,” it added.

It said an investigative team led by the deputy prosecutor general of Azerbaijan has been dispatched to Kazakhstan and is working at the crash site.

Survivors ‘covered in blood’

A Kazakh woman told the local branch of Radio Free Europe/Radio Liberty (RFE/RL) that she was near where the plane crashed and rushed to the site to help survivors.

“They were covered in blood. They were crying. They were calling for help,” said the woman, who gave her name as Elmira. She said they saved some teenagers.

“I’ll never forget their look, full of pain and despair,” said Elmira. “A girl pleaded: ‘Save my mother, my mother is back there’.”

The health ministry said a special flight was being sent from the Kazakh capital Astana with specialist doctors to treat the injured.

Russian President Vladimir Putin held a phone conversation with Aliyev and “expressed his condolences in connection with the crash”, his spokesman Dmitry Peskov told a news conference.

A Russian emergency situations ministry had been sent to Aktau with medical personnel and other equipment, Putin said later as he opened the CIS leaders’ meeting in Saint Petersburg.

Azerbaijan’s first lady Mehriban Aliyeva, who is also the country’s first vice president, said she was “deeply saddened by the news of the tragic loss of lives in the plane crash near Aktau”.

“I extend my heartfelt condolences to the families and loved ones of the victims. Wishing them strength and patience! I also wish a speedy recovery to the injured,” she said on Instagram.

Chechen leader Ramzan Kadyrov said on Telegram: “I express my condolences to the relatives of the passengers of the Azerbaijan Airlines jet who died.”