WASHINGTON<$> — The United States yesterday accused Syria, Iran and Hezbollah militants of plotting to topple the Lebanese government and warned them to keep their “hands off”.The United States has held up Lebanon as an example of emerging democracy in the Middle East. “We are therefore increasingly concerned by mounting evidence that the Syrian and Iranian governments, Hezbollah, and their Lebanese allies are preparing plans to topple Lebanon’s democratically elected government,” White House spokesman Tony Snow said in a statement. US officials declined to give evidence of the accusations, saying the information was classified.