The joint training exercise "Border 2016" was held around the southwestern towns of Bulgaria, Petrich, Sandanski and Kulata on Saturday.The exercise aims to coordinate the activities of the Interior Ministry and the Ministry of Defense to react in case of possible migration flow."400 officers from the army, gendarmerie and police will remain permanently at the border. We have the capacity of deploying more people and equipment," said Bulgarian Prime Minister Boyko Borisov, speaking to the media after the drill."We want our citizens to sleep in peace," the country's head of defense Lieutenant-General Konstantin Popov said.Bulgaria last week passed a law that stipulated the army would assist in border protection.The representatives of the Red Cross in Bulgaria also participated in the exercises.During the exercises the border facilities of Kulata were closed for an hour.The Greek authorities have been racing to prepare for larger numbers of refugees remaining in Greece for longer periods as countries along the Balkan route to Europe have put increased frontier restrictions in place.The number of the migrants stuck at the Macedonia-Greek border has been rising after new regulations were implemented by Balkan countries, limiting the entries of migrants to 500 a day.Therefore, the new regulations led a sharp increase in the number of refugees in Greece, which currently stands at more than 22,000.Immigration Minister Giannis Mouzalas said Greece awaited up to 70,000 refugees next month as the weather in the Aegean Sea is expected to improve.In recent weeks, Austria has placed strict limits on the inflow of migrants, causing a domino effect through the Balkans and leading to criticism from other EU members and refugee agencies.Athens has threatened to block decisions at an EU-Turkey summit on Monday unless the EU forces members to take their share of refugees.