A police official told the Associated Press that a suicide bomber killed two people at the entrance of the US embassy in Ankara, Turkey.
Turkish commercial station NTV said two security guards at the entrance were killed.
More top news
Former Davis Cup finalist John Lloyd led the tributes to Andy Murray, who ended Great Britain's 79-year wait for the famous trophy
Scotland's Justice Minister is under pressure from political opponents over revelations Police Scotland carried out illegal surveillance.
Andy Murray has beaten Belgian David Goffin to win the Davis Cup for Great Britain for the first time since 1936