BRUSSELS/WARSAW, Sept 24 (Reuters) - The EU executive expressed concern on Friday over the plight of migrants stuck on the Polish-Belarusian border and urged Warsaw to protect human lives and allow the bloc"s joint frontier force Frontex to provide assistance in the area. Three migrants died on the Polish side of the border and one more just inside Belarus earlier this week while trying to cross into Poland. The causes of death have not been given. A fifth death - of an Iraqi man just inside Poland, probably from a heart attack - was reported on Friday. read more Poland and the EU have accused Belarus of encouraging migrants from Iraq, Afghanistan and African countries to cross the border in order to put pressure on the bloc over sanctions Brussels has imposed on Minsk for human rights abuses. "We recognise that the Polish authorities are dealing with a difficult situation. The situation has been created by an attempt to instrumentalise people for political purposes," a spokesman for the European Commission told a news conference. But Poland must carry out its border management duties without endangering human life or denying people necessary care, he said, adding: "The situation is very concerning." "It would be a good idea for our shared border to be protected using our shared resources, namely those provided by the agency (Frontex)," the spokesman said. STATE OF EMERGENCY Poland, which has one of the biggest border forces in the EU, has not requested Frontex assistance, though the agency is helping in nearby Lithuania and Latvia, which also share a border with Belarus. Warsaw has introduced a state of emergency along its border with Belarus, meaning no journalists, politicians or rights activists are allowed into the area. The Commission said the EU"s top migration official, Ylva Johansson, wanted to discuss with Warsaw on Friday financial and other assistance the bloc can provide, including a Frontex deployment and a visit by EU experts to the border zone. Poland"s Interior Minister Mariusz Kaminski said Johansson was not in touch. The ministry did not respond to a Reuters request for comment. The Polish and Lithuanian interior ministries agreed separately on Friday to push for EU financing for a border fence between their countries and Belarus. Poland"s handling of the border situation has further strained relations with the EU over migration. The ruling Law and Justice (PiS) party has resisted EU pressure to take in some of the mostly Muslim migrants trying to enter Europe, seeing them as a threat to national security and to Poland"s Christian culture and identity. The Commission and rights groups fear that Poland is forcing migrants at the border back into Belarus, violating their right to seek asylum and putting them at greater risk. U.N. human rights chief Michele Bachelet called on Belarus" neighbours on Friday to protect asylum seekers following the deaths on the Polish border. read more