A small explosion occurred today near a commercial building in Tehran housing the offices of British Airways and British Petroleum. There were no casualties. A spokeswoman for the British embassy said the device was placed in a dustbin in the hallway of the building. British Ambassador John Dalton said it's not clear who the target for the explosion was and added: "We do not know who the target of the explosion was. The Iranian authorities responded very quickly and I'm grateful for that. I will be consulting them about additional precautions which may be necessary for British companies." The explosion caused some material damage.