Kazakhstan unrest: At least 164 killed in crackdown on protests

If confirmed it would mark a sharp rise from the previous figure of 44 deaths.

Almost 6,000 people have been arrested, including "a substantial number of foreign nationals", Kazakhstan's presidential office said on Sunday.

The demonstrations, triggered by a rise in fuel prices, turned into huge riots as they spread across the country.

They started on 2 January and grew to reflect discontent at the government and former President Nursultan Nazarbayev, who led Kazakhstan for three decades and is still thought to retain significant influence.

VIDEO: Soyuz spacecraft lifts off for the ISS

The rocket lifted off at 3:02am local time on Wednesday (2102GMT on Tuesday) and is to dock with the orbiting laboratory about six hours later.

The capsule is carrying Oleg Kononenko of Russia, NASA's Kjell Lindgren and Kimiya Yui of Japan.

They will join Gennady Padalka, Mikhail Kornienko and Scott Kelly.

The latter two are more than four months into a nearly year-long mission on the space station.

Russian capsule takes off for International Space Station

The rocket lifted off at 3:02 a.m Thursday (2102 GMT Wednesday) and was to dock with the orbiting laboratory about six hours later. It reached orbit about 15 minutes after launch and is to circle the Earth four times before heading for the space station, which is about 250 miles (400 kilometers) above the Earth.