UPDATE 6-Israel hits Syria arms convoy to Lebanon -sources

* Arms convoy hit on Lebanon-Syria border, sources say * Syria accuses Israel of bombing military site * Israel has warned it could hit Syria to stop arms spread * Key concern is anti-aircraft missiles reaching Hezbollah (Adds sources on chemical weapons) BEIRUT, Jan 30 (Reuters) - Israeli jets bombed a convoy nearSyria's border with Lebanon early on Wednesday, sources toldReuters, apparently ...