The Israeli embassy in London was put on high alert after an envelope containing white powder was delivered.
The powder was tested and determined to be harmless Monday. Officials believe that the sender wanted to scare embassy workers.
Embassy staff returned to work once it was clear that the powder posed no threat.
Shoes were found Monday morning on the private road leading to the Israeli embassy in London, following demonstrations that turned violent and were broken up by riot police. The shoes were likely thrown at the barrier blocking the entrance to the road by demonstrators.