The Russian Defense Ministry said on Saturday that its troop contingent sent to Kazakhstan to help stop violent unrest in the central Asian country has returned home.

The Russian troops were part of a "peacekeeping force" numbering around 2,000 deployed by the Collective Treaty Security Organization (CSTO), which is a Russia-led coalition made up of six former Soviet states, including Belarus, Armenia, Tajikistan and Kyrgyzstan.

Russia's defense ministry tweeted that the troops and equipment had arrived, saying all planes with Russian peacekeepers from the "collective peacekeeping forces of the CSTO" arrived from Kazakhstan at the Severny air base near the city of Ivanovo. 

The CSTO began a phased withdrawal of troops on Wednesday, which is set to continue until January 19. It is unclear if troops from other CSTO countries remain in Kazakhstan. 

Why were Russian troops in Kazakhstan? 

According to a tweet from CSTO secretary-general, Stanislav Zas, there were no clashes between the peacekeeping force and "militants" during the troops' deployment in Kazakhstan.

The forces were mustered after a plea for assistance from Kazakh President Kassym-Jomart Tokayev.

Violent unrest broke out in the former Soviet nation after protests over rising fuel prices spread across the country.

The demonstrations morphed into wider discontent against President Tokayev's government.

In Almaty, the former capital and largest city in Kazakhstan, protesters set fire to government buildings and briefly took control of the airport.

Tokayev announced a state of emergency and gave a shoot-to-kill order to security forces — sparking international condemnation. 

The president also claimed the protests were sparked by foreign-backed "terrorists" but did not provide any evidence.

The Health Ministry briefly reported that over 160 people had been killed in the unrest, although the report was later deleted without a reason being provided. Dozens of people were also injured. Around 12,000 people have been arrested in the aftermath of the demonstrations.

The Kazakh government said the situation has been stabilized.

kb/wmr (AP, dpa)