MOSCOW, Jan 7 (Reuters) - Belarus"s state news agency said President Alexander Lukashenko had spoken by phone on Friday with Nursultan Nazarbayev, the former leader of Kazahstan who was the target of popular anger this week in mass protests that swept the Central Asian country. It was the first public mention since the start of the unrest of any official contact involving Nazarbayev, who stepped back from the presidency in 2019 but continued to wield power behind the scenes as head of Kazakhstan"s Security Council. President Kassym-Jomart Tokayev removed him from that position on Wednesday after the protests spread across the vast steppe nation, which is located between Russia, China and three other ex-Soviet republics. The Belta news agency said Lukashenko and Nazarbayev "discussed in detail the state of affairs in Kazakhstan", but provided no further information. Security forces appeared to have reclaimed the streets of Kazakhstan"s main city, Almaty, on Friday, a day after Russian paratroopers began to arrive to help restore order after days of violence in which dozens were killed and public buildings torched. read more Lukashenko also faced mass street protests last year against his rule following a disputed election, and had to turn to Russia for financial and military support to stay in power. Nazarbayev"s whereabouts remain unclear, amid speculation and conflicting reports that he may seek to leave the country or may already have left. The 81-year-old former Communist Party boss ruled Kazakhstan unchallenged for nearly three decades after the 1991 collapse of the Soviet Union and he and his family amassed substantial wealth. This week"s unrest began with fuel price protests but quickly exploded into a wider surge of anger directed against Nazarbayev, with crowds chanting "Old man, go away!"