By CHRISTOPHER TORCHIAAKINCI, Turkey (AP) â¿¿ For two people walking into a Turkish minefield, they looked awfully assured. The pair strode in from Syria on a recent afternoon, following a faint track across the grassy plain. They slipped into Turkey through a fence near a vacant military watchtower and vanished into an olive grove. Such hazardous crossings are a smuggler's tradition at the border, where Turkish plans to clear a vast belt of land mines have been clouded by Syria's civil war. Last week, Turkey asked NATO allies to deploy Patriot missiles as a defense against any aerial attacks from Syria after shells and bullets spilled across the border, killing and injuring some Turks. Starting in the 1950s, Turkish forces planted more than 600,000 U.S.-made "toe poppers" â¿¿ mines designed to maim, not kill â¿¿ and other land mines along much of its 900-kilometer (560-mile) border with Syria, which runs from the Mediterranean Sea to Iraq. The aim was to stop smugglers whose cheap black market goods undercut the Turkish economy and later to thwart Kurdish rebels from infiltrating Turkey's southeast. However, the mines also killed and maimed civilians, took arable land from Turkish farmers and are now considered by many as a crude method of policing. Turkey says it plans to clear anti-personnel mines on the Syria border by 2016, missing a March 2014 deadline required by the international Mine Ban Treaty. The International Campaign to Ban Landmines, a Geneva-based group that won the 1997 Nobel Peace Prize, has criticized Turkey for its slow progress. The European Union has committed â¿¬40 million ($52 million) to demining and surveillance equipment near Turkey's borders with Iran and Armenia on the basis that Turkey could eventually become the EU's most eastern border. Turkey, adjacent to the Middle East and Central Asia, has long been a drug trafficking route and a transit point for migrants who enter Europe illegally.