United States federal investigators say two planes crashed more than 600 miles (1,000 kilometres) apart in Alaska almost simultaneously Saturday, killing a total of four people.

The National Transportation Safety Board said two died and a third person was injured when a Piper PA-30 went down nine miles (15 kilometres) southwest of Haines, Alaska at around 11 a.m. The injured person was flown by helicopter to Juneau for medical treatment.

Authorities said witnesses reported seeing the twin-engine plane crash shortly after takeoff.

The Fairbanks Daily News-Miner reports two people died in another crash when a single-engine Arctic Aircraft S-1B2 crashed east of Fairbanks, also at about 11 a.m.

Alaska State Troopers reported late Saturday that both the pilot and passenger died in that crash.