Israeli intelligence has collected evidence proving a senior Palestinian police commander ordered a squad under his command to ambush Israeli cars in the West Bank, a government official said. The official, speaking on condition of anonymity, said Israel had electronically intercepted the orders handed down from the Gaza police chief, Brig. Gen. Ghazi Jabali. Israel arrested three Palestinian policemen in possession of plans to ambush Israeli cars near Jewish settlements, the official said. Palestinian leader Yasser Arafat appointed a committee to investigate.