US wildlife officers in Washington state have shot dead a cougar that killed a cyclist and mauled another.

The two cyclists were in North Bend, about 30 miles (50km) from Seattle, when the attack occurred. The injured man used his mobile phone to seek help.

The rider who died was dragged away by the cougar to its den, said King County sheriff spokesman Sergeant Ryan Abbot.

Wildlife officials said it was only the second fatal cougar attack in Washington state in the past 100 years.

Tracker dogs were used to locate the animal, hours after the attack.

Cougars – also known as mountain lions – are the fourth largest cat species in the world, but they rarely attack humans.

Wildlife officials however say more cougar attacks have been reported in the western US and Canada over the past 20 years than in the previous 80.