SYDNEY, July 1 (Reuters) - The Australian government issued an upgraded travel alert for Britain on Sunday, advising visitors to use a high degree of caution. This is the third-highest degree of warning on a five-point scale, falling just short of advising travellers to reconsider visiting a country. It put Britain on a par with Iran, India, Guatemala, Jordan and Kuwait for potential threats posed to Australian travellers. "In response to the events in the last 48 hours in London and Glasgow, the United Kingdom authorities have raised the UK threat level to 'critical'," the Australian Department of Foreign Affairs said in a statement posted on its Web site on Sunday. "This is the highest level and means that a terrorist attack is expected imminently," it said. On Friday two car bombs were defused in central London. On Saturday a blazing vehicle was driven into the main terminal at Glasgow airport.
