By JARI TANNER
HELSINKI (AP) — Finland says it will extend the closure of its border with Russia for another month because it suspects that Moscow is trying to undermine the Nordic country’s security by sending undocumented migrants across the frontier. Finland closed the border late last year after 1,300 migrants without proper documentation or visas had arrived across the frontier since September _ an unusually high number, just months after Finland joined the NATO alliance. Finland accuses Russian of deliberating ushering the migrants to its normally heavily controlled border. The Kremlin denies the allegation, and says it regrets the Finnish border closures. The latest closure applies to passengers but not cargo trains, and will last until Feb. 11.