The anxiety generated by nonstop media coverage of the wave of Palestinian violence appears to be taking its toll.Passengers on a northbound train that was traveling from Haifa on Thursday hit the emergency brakes in between stations after a group of female soldiers mistakenly believed that an Arab sitting nearby was armed with a knife. Four people were treated for light injuries and shock.When the soldiers screamed "there's a terrorist on board," another passenger, an IDF officer, fired his gun into the air.Shortly afterward, the emergency brakes were activated, and the train came to a sudden halt, according to Israel Radio. The passengers then evacuated the train's cars in a panic, although a short time later it became apparent that there was no threat from any passenger on board.Authorities are now questioning the officer in order to ascertain what led him to fire his weapon."I was at the train station in Haifa, and the train on the other track opposite of the platform where I was standing began to move," an eyewitness told Channel 2. "A short time later, the train stopped suddenly, and police and security guards began running toward it.""They demanded that all of the passengers exit the train, and I heard them scream 'There's a terrorist on the train'," he said. "There was huge chaos, and there were a lot of police who arrived on the scene within a short time."