Azerbaijan’s transport minister has said the Azerbaijan Airlines plane that crashed on 25 December was subjected to “external interference” and damaged inside and out, as it tried to land in Russia’s southern republic of Chechnya.

“All [the survivors] without exception stated they heard three blast sounds when the aircraft was above Grozny,” said Rashad Nabiyev.

The plane is thought to have come under fire from Russian air defence systems before being diverted across the Caspian Sea to Kazakhstan, where it crashed with the loss of 38 lives.

The Kremlin has refused to comment, but the head of Russia’s civil aviation agency said the situation in Grozny was “very complicated” at the time and a closed-skies protocol had been put in place.

“Ukrainian combat drones were launching terrorist attacks on civilian infrastructure in the cities of Grozny and Vladikavkaz,” said Dmitry Yadrov, head of Rosaviatsia, in a video statement posted on Russia’s Tass news agency.

“Because of this a ‘Carpet plan’ was introduced in the area of Grozny airport, providing for the immediate departure of all aircraft from the specified area,” he said. “In addition, there was dense fog in the area of Grozny airport.”

Later on Friday White House spokesperson John Kirby told reporters that the US had seen “early indications” that the plane may have been downed by Russian air defence, but declined to comment further.

The Washington Post reported Kirby had said the indications the US had seen went beyond the widely-circulated photos of the damaged plane.

Ukrainian presidential spokesman Andriy Yermak has said Russia must be held responsible.

Azerbajian Airlines said on Friday that a preliminary inquiry had blamed both “physical and technical external interference”, without going into details.

However, aviation experts and others in Azerbaijan believe the plane’s GPS systems were affected by electronic jamming and it was then damaged by shrapnel from Russian air-defence missile blasts.

The transport minister said investigators would now examine “what kind of weapon, or rather what kind of rocket was used.”

The government in Baku has so far avoided directly accusing Russia, possibly to avoid antagonising President Vladimir Putin.

However, pro-government MP Rasim Musabekov was clear: “The plane was shot down over Russian territory, in the skies above Grozny. Denying this is impossible.”

He told AFP news agency the plane had been damaged and the pilot had asked to make an emergency landing in Grozny. Instead of being directed to nearby airports, he said it was “sent far away” across the Caspian Sea without GPS.

Flight attendant Zulfuqar Asadov described the moments when the plane was hit by “some kind of external strike” over Chechnya.

“The impact of it caused panic inside. We tried to calm them down, to get them seated. At that moment, there was another strike, and my arm was injured.”

Veteran Azerbaijani pilot Tahir Agaguliev told Azerbaijani media that shrapnel had damaged the hydraulics that controlled the plane: “The missile itself did not hit the plane; it was shrapnel from the missile that struck. The missile exploded about 10m (30ft) away, before reaching the plane.”

The pilots of the Embraer 190 plane are credited with saving 29 of those on board by managing to land part of the plane, despite themselves being killed in the crash.

The Kremlin has refused to comment on the increasing number of reports that the Azerbaijan Airlines plane was hit by Russian air defence.

“An investigation into this aviation incident is underway and until the conclusions are made as a result of the investigation, we do not consider ourselves entitled to give any assessments,” said spokesman Dmitry Peskov.

Azerbaijan is looking for a Russian apology, or at least an acknowledgement, that the plane was hit by its air defences in Grozny, according to figures close to the government in Baku.

Four years ago, Baku apologised an offered compensation when a Russian air force Mi-24 helicopter was shot down at the end of the 2020 war in Nagorno-Karabakh.

“Now the Azerbaijani side is also expecting Russia to take those steps,” said political commentator Farhad Mammadov.

Kazakh authorities have been treating the injured and working closely with Azerbaijan on the investigation.

Officials say the Brazilian plane manufacturer Embraer has sent two specialists to the crash site, 3km (1.9 miles) from Aktau airport in Kazakhstan, and three members of Brazil’s aviation agency will arrive on Saturday.

Reports in Baku suggest both Russia and Kazakhstan have proposed having a committee from the Commonwealth of Independent States (CIS) – a regional organisation dominated by Russia – investigate the crash, but Azerbaijan has instead demanded an international inquiry.

Azerbaijan Airlines and several other airlines have suspended flights to some Russian cities in response to the crash.

In a social media post, the airline said this was “for security reasons”. It had already halted flights to Grozny and Makhachkala in neighbouring Dagestan, but has now added the cities of Sochi, Volgograd, Ufa, Samara and Mineralnye Vody.

Israel’s flagship airline, El Al, has meanwhile suspended all flights to Moscow, citing developments in Russian airspace, and UAE-based budget carrier Flydubai has halted flights to Sochi and Mineralnye Vody.