Syria has reinforced its border with Lebanon with rocket units and thousands of troops, eight Syrian and Lebanese sources said on Tuesday, as conflict spread in the region including between Israel and Hezbollah in Lebanon.The sources included five Syrian military officers, a Syrian security official and two Lebanese security officials who spoke on condition of anonymity.For all the latest headlines, follow our Google News channel online or via the app.The Syrian officers said the Syrian reinforcement operation began in February but sped up in recent days. The Syrian and Lebanese armed forces did not immediately respond to requests for comment.The Syrian officers, including a senior member of the military, said the move was aimed at preventing arms and drugs smuggling as well blocking Iran-backed Lebanese Hezbollah or other militants from infiltrating Syria.A Syrian officer told Reuters that military formations from several Syrian army divisions, including the 52nd and 84th Divisions,