Unions plan London 3-day undergound strike

LONDON (Reuters) - Workers at London's underground have voted to strike for 72 hours from April 6 over a series of grievances, a move that could cause travel chaos in the capital.

Transport unions the RMT and TSSA -- the two biggest unions representing more than 7,500 workers -- will start the strike at at 6.30pm (1730 GMT), they said in a joint statement on Friday.

The unions said the disputed issues included ticket office closures, lone working, and the use of agency and security staff which they called an unacceptable attack on safety standards.

"This is a dispute about the safety of our Tube system. The last people we want to hit are the travelling public but this seems to be the only way we can make LU (London Underground) listen," TSSA general secretary Gerry Doherty said in the statement.