TWO people were rescued from a small plane early today in the United States several hours after they crashed into power lines, causing widespread outages in the surrounding part of Maryland.

The crash took place at Gaithersburg, a city of 69,000 people about 24 miles north-west of Washington.

The two men on board were rescued from the aircraft, which was stuck about 100 feet above the ground.

Montgomery County Fire Chief Scott Goldstein said both men suffered serious injuries from the crash and had been transported to local trauma centres. 

The Federal Aviation Administration (FAA) said the single-engine Mooney M20J plane, which had departed White Plains, New York, crashed into a power-line tower near Montgomery County Airpark in Gaithersburg at about 5.40pm on Sunday.

Power firm Pepco reported that about 120,000 customers had been without power in Montgomery County but most of the power had been restored except for the crash site. 

The cause of the crash was not immediately clear. The FAA and National Transportation Safety Board are set to investigate.