AMMAN - Syrian police killed two protesters on Tuesday when they opened fire on a crowd who came out to welcome United Nations observers in the eastern province of Deir al-Zor, a rebel official said."As soon as the UN convoy entered al-Busaira a jubilant crowd of hundreds came out to welcome them. It was not minutes before they came under fire," Abu Laila, a Free Syrian Army official, said by phone from the town.There was no independent confirmation of the incident.