Britain's ambassador in Tehran was reportedly arrested and briefly detained by Iran for being involved in student protests against the accidental downing of the Ukraine plane. <br />'' <br />'' Iran's semi-official news agency, Tasnim, claimed that Britain's envoy to Tehran Rob Macaire was arrested for hours for his involvement in provoking suspicious acts in a gathering held in front of Tehran Amir Kabir University yesterday. <br />'' <br />'' He was freed a few hours later but will be summoned today for further explanations. Britain's Foreign Secretary Dominic Raab, in a statement said, the arrest of UK ambassador in Tehran without grounds or explanation is a flagrant violation of international law.<br />''