Britain turned up the heat on Iran yesterday, releasing evidence it said showed 15 military personnel captured last week were operating in Iraqi waters and freezing bilateral contacts until the crisis is resolved.

Iran countered by insisting that British marines and sailors were inside Iranian waters and said the governments of both countries could settle the matter through "close cooperation".

Britain's Foreign Office said however that until the detainees were returned it would halt all official visits between the two countries, suspend the issue of visas to Iranian officials and suspend support for events such as trade missions.