BEIRUT – Turkey warned Syria on Tuesday to keep its forces away from the countries’ troubled border or risk an armed response – a furious reply to the downing of a Turkish military plane last week by the Damascus regime.

NATO backed up Turkey and condemned Syria for shooting down the plane but stopped short of threatening military action, reflecting its reluctance to get involved in a conflict that could ignite a broader war.

Near the capital of Damascus, meanwhile, Syria’s elite Republican Guard forces battled rebels in some of the most intense fighting involving the special forces since the uprising against President Bashar Assad’s regime began in March 2011, according to activists.