Explosion occurred Friday not far from the United Nations Office at Geneva was caused by a fire at a construction site, said local police. Christophe Fortis, Geneva Cantonal Police spokesman, told Xinhua that a gas canister exploded due to a fire in the building site out of the Graduate Institute of International and Development Studies (IHEID). It caused no injuries or death, he said. The explosion happened at 12:45 p.m. (1145GMT) and residents nearby heard loud sound of explosion and saw black smog coming out of the building.