U.N monitors in Ukraine also report serious problems emerging in Crimea, Navi Pillay said, especially in relation to the minority Crimean Tatar population.While many peaceful rallies take place in Ukraine, the findings also show "an increasing tendency in some critical urban areas for rallies of opposing groups to be held simultaneously, often leading to violent confrontations," according to a statement from Pillay's office.The 36-page report also notes "repeated acts of violence against peaceful participants of rallies, mainly those in support of Ukraine's unity and against the lawlessness in the cities and villages in eastern Ukraine.""In most cases, local police did nothing to prevent violence, while in some cases it openly cooperated with the attackers," it states.The report, compiled by 34 U.N. monitors on the ground, covers the period from April 2 to May 6.Unrest in eastern Ukraine has increasingly flared into violence in recent weeks, as pro-Russia separatists clash with rival groups and Ukrainian security forces.In Friday's statement, Pillay urged "those with influence on the armed groups responsible for much of the violence in eastern Ukraine to do their utmost to rein in these men who seem bent on tearing the country apart."Pro-Russia activists in the eastern regions of Donetsk and Luhansk staged a referendum on independence last weekend, which was dismissed as illegitimate by Kiev and the West.Ukraine's southeastern Crimea region was annexed by Russia in March following a separate controversial referendum.Russian speakers make up a majority of the Black Sea peninsula's residents, but about 12% are Crimean Tatar, a predominately Muslim minority which was oppressed during the Soviet era.Billionaire opposes split from UkraineOne of the richest men in the world, Donetsk-based steel and iron ore billionaire Rinat Akhmetov, took a public stand against pro-Russian separatists in eastern Ukraine in a video message Wednesday.Akhmetov said he favored a decentralization of power under a new constitution in Ukraine, but opposed his region joining Russia or trying to remain an independent "Donetsk People's Republic."Either scenario, he said, would result in sanctions, and a loss of jobs and industry.Forbes magazine lists Akhmetov as the 92nd richest man in the world, worth $12.2 billion.On Thursday, representatives of one of his companies in the restive eastern Ukrainian city of Mariupol co-signed a memorandum calling for public order and security after armed conflict in the city on May 9.Ukraine's interim government is looking at constitutional reforms ahead of presidential elections scheduled for May 25.(CNN)Bakudaily.az