• In this Sunday Feb. 15, 2015 file photo and provided on by the Syrian anti-government activist group Aleppo Media Center (AMC), which has been authenticated based on its contents and other AP reporting, shows Syrian rebels firing locally made shells against the Syrian government forces, in Aleppo, Syria. Islamic State militants entered a Syrian opposition stronghold in the country's north on Saturday, clashing with rebels on the edges of the town as the extremist group built on its most significant advance near the Turkish border in two years, Syrian opposition groups and IS media said. (AP Photo/Aleppo Media Center, AMC, File)

    Syria rebels under fire from IS militants, government troops

    BEIRUT (AP) — Islamic State militants entered a major Syrian opposition stronghold in the country’s north on Saturday, clashing with rebels on the edges of the town as the extremist group builds on its most significant advance near the Turkish border in two years — even as it loses ground elsewhere in the country and in neighboring Iraq.