BRUSSELS/VYDENIAI, Lithuania, July 12 (Reuters) - Lithuania"s foreign minister and the EU"s top diplomat accused Belarus on Monday of using illegal migrants as a political weapon to put pressure on the European Union because of the bloc"s sanctions on Minsk. Belarus was flying in migrants from abroad and sending them over the border into EU countries, minister Gabrielius Landsbergis said at a meeting of EU foreign ministers in Brussels. "When refugees are used as a political weapon...I will talk to my colleagues in order for the European Union to have a common strategy," Landsbergis said. His words were later echoed by Josep Borrell, the EU"s foreign policy chief, who said: "To use migrants as a weapon, pushing people against the borders, is unacceptable." The EU should consider expanding economic sanctions that were imposed on Belarus in June, Borrell said. Nearly 1,700 migrants have entered Lithuania, an EU state, illegally from Belarus this year, more than 1,000 of them in July alone, according to Lithuania"s border guard service. Half of them identified themselves as Iraqi citizens. Landsbergis suggested the migrants were being turned into a means of pressure on the EU, which has imposed a series of sanctions on Belarus since a disputed presidential election last August that was followed by a police crackdown on street protests. "We need to be very strict with the regimes that are using these sorts of weapons, first of all with sanctions," he said. Lithuanian EU lawmaker Rasa Jukneviciene told a meeting with EU and Lithuanian officials that Belarus and Russia were organising human smuggling networks with the help of Iran to fly people to the Lithuanian border, although she did not provide any evidence. Minsk and Moscow deny any such operations. Last month, the EU imposed broad economic sanctions on Belarus" main export industries, and on banks and finance, to try to hit sources of revenue for President Alexander Lukashenko, who has been in power since 1994. EU leaders were outraged when Belarusian authorities intercepted a passenger plane flying between Athens and Vilnius on May 23 and arrested a dissident journalist and his girlfriend who were on board. Lukashenko said last week his government would not close its borders with its neighbours and become a "holding site" for migrants from the Middle East, Asia and Africa. Reuters requested further comment from Belarus on Monday. Lithuania began building a 550-km (320-mile) razor wire barrier on its frontier with Belarus on Friday. ABANDONED A migrant from Somalia who spoke to Reuters in a temporary detention site in Lithuania said her group had been told they could pay $7,000 on arrival for transit to Lithuania. They were now being held in cramped, unsanitary conditions, she said. read more The woman, who identified herself as Kauthar, 19, said she had fled war and domestic violence in her native Somalia, flying to Minsk via Istanbul, but had been abandoned in open country around the Belarus-Lithuania border because she could not pay the transfer fee. It was not clear who had arranged the journey in Mogadishu, or who had abandoned the migrants in Belarus. She was speaking to Reuters through a fence erected around a disused school in the Lithuanian village of Vydeniai that has been turned into a detention facility. The main detention centre in Pabrade is full and migrants are being temporarily housed in sites scattered near the border area. The EU border guard agency Frontex said on Monday it would send additional officers, patrol cars and experts to talk to migrants that have reached Lithuania to gather information on criminal networks. "The situation at Lithuania"s border with Belarus remains worrying. I have decided to send a rapid border intervention to Lithuania to strengthen the EU"s external border," Frontex Executive Director Fabrice Leggeri said in a statement. Leggeri later told EU officials and lawmakers that Frontex was preparing to fly migrants out of Lithuania with a mix of commercial and charter flights for those not granted refugee status by Vilnius.