Britain's aviation authority BAA today announced a preliminary halt to plans to expand the Heathrow and Stansted airports after years of controversy, according to dpa. BAA had planned to build a third runway at Heathrow and also had expansion plans for Stansted, 80 kilometres north of London, plans which local communities had protested against for years. The move to put the plans on ice for now was seen as a formality, as the new Conservative-Liberal coalition government had announced its aim to stop the airports' expansion. Meanwhile environmental activists in Manchester broke through airport fences on Monday and ran onto the runway, causing a 20-minute interruption of air traffic. Police arrested 17 activists, who were protesting against expansion work on the Manchester airport's cargo terminal.