Washington's metro train system will shut all day Wednesday for emergency inspections after an electrical fire in a tunnel earlier this week, transport officials said, in a move that threatens to cause mass disruption in the US capital. 

"We will suspend rail service for 24 hours to inspect 600 underground jumper cables. The entire rail system will be closed until 5:00 am Thursday," Paul Wiedefeld, general manager of the Washington Metropolitan Area Transit Authority, told a news conference.