Kiev, Nov 28 : The Ukrainian forces have conducted staff exercise at the frontier with Belarus, as a part of the operation "Polissya" that is aimed at preventing a migrant crisis, the State Border Guard Service (SBGS) of Ukraine has said. The exercise, which started on November 23, was conducted by the SBGS together with the National Guard, the National Police, the Armed Forces and other law enforcement units of Ukraine. The maneuvers were held at four different parts of the border in Ukraine's northern Chernihiv region, the SBGS said in a statement on Saturday, Xinhua news agency reported. According to the statement, the main task of the exercises is to obtain the necessary skills to act in response to any abrupt changes in the situation on the border. As a part of the operation, the Ukrainian authorities have increased the number of border patrol servicemen and equipment at the frontier to prevent possible attempts of illegal migrants to break through the border. Ukraine used aviation, unmanned aerial vehicles and technical means of surveillance during the operation. Since August, thousands of migrants, mostly from war-torn countries in the Middle East, attempted to enter the European Union (EU) yet are stranded at the border between Belarus and the EU. Ukraine shares about 1,084 km of border with Belarus in the north. /IANS