The US city of Seattle has inaugurated its 22.5km (14 mile) Central Link light rail line connecting the city to Tukwila.

The $2.3bn line connects downtown Seattle to the 154th Street station in Tukwila, covering 12 stations and running through a 2.1km downtown tunnel.

The new line will take 30 minutes to travel between Seattle and Tukwila, with trains available every 7.5 to 15 minutes. In the beginning, the service is expected to carry about 21,000 passengers daily.

The line will also be extended by 2.4km to Sea-Tac International Airport in December and by 5km underground from downtown Seattle to the University of Washington in 2016.

The network is expected to cater to 42,500 passengers daily by 2020.