An Azerbaijan Airlines passenger jet with 67 people on board crashed on Wednesday in western Kazakhstan after veering from its scheduled route, officials said.

Azerbaijani authorities said 32 people had survived the crash of the Embraer 190 near the city of Aktau, an oil and gas hub on the eastern shore of the Caspian Sea.

The plane was flying from the Azerbaijani capital Baku on the western shore of the Caspian to the city of Grozny in Chechnya in southern Russia.

"A plane doing the Baku-Grozny route crashed near the city of Aktau. It belongs to Azerbaijan Airlines," the Kazakh transport ministry said on Telegram.

Azerbaijan Airlines, the country's flag carrier, said the plane had 62 passengers and five crew on board.

It said the plane "made an emergency landing" around three kilometres (1.9 miles) from Aktau.

Azerbaijani President Ilham Aliyev cancelled a planned visit to Russia for an informal summit of leaders of the Commonwealth of Independent States, a grouping of former Soviet nations.

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

The office of Azerbaijan's prosecutor general said: "According to available data, 32 people survived the crash."

"We cannot disclose any investigation results at this time. All possible scenarios are being examined, and the necessary expert analyses are underway," it said in a statement.

"An investigative team, led by the deputy prosecutor general of Azerbaijan, has been dispatched to Kazakhstan and is working at the crash site."

Doctors flown to site

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

The ministry earlier reported that "28 survivors including two children have been hospitalized."

It said 150 emergency workers were at the scene.

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

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.

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

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.

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

The plane's course on Flight Radar showed it crossing the Caspian Sea away from its normal route and then circling over the area where it eventually crashed.

Kazakhstan said it had opened an investigation.