A Moscow-led military alliance dispatched troops to help quell mounting unrest in Kazakhstan on January 6 as police said dozens were killed trying to storm government buildings.

Long seen as one the most stable of the ex-Soviet republics of Central Asia, energy-rich Kazakhstan is facing its biggest crisis in decades after days of protests over rising fuel prices escalated into widespread unrest.

Under increasing pressure, President Kassym-Jomart Tokayev appealed overnight to the Russia-dominated Collective Security Treaty Organisation (CSTO), which includes five other ex-Soviet states, to combat what he called “terrorist groups” that had “received extensive training abroad”.

Within hours the alliance said the first troops had been sent – including Russian paratroopers and military units from the other CSTO members – in its first major joint action since its founding in 1999.

“Peacekeeping forces … were sent to the Republic of Kazakhstan for a limited time to stabilise and normalise the situation,” the CSTO said in a statement, without specifying the number of troops involved.

The CSTO’s current chairman, Armenian Prime Minister Nikol Pashinyan, earlier announced the alliance would agree to the request, saying Kazakhstan was facing “outside interference”.

Footage released by the Russian defence ministry showed military transport planes being loaded with troops and armoured trucks before taking off from a snowy runway for Kazakhstan.

In the worst reported violence so far, police said dozens of people were killed in overnight battles with security forces at government buildings in the country’s largest city Almaty.