US fighter jets intercepted two small planes over Camp David, the US presidential retreat, in separate incidents on Saturday, the North American Aerospace Defense Command announced.

A Cessna 210 was intercepted at 6:56 pm local time (2256 GMT), said the bi-national US and Canadian command responsible for the air defense of North America and responding to unknown or unauthorised air activity.

The fighters escorted the plane to the Carroll County Regional Airport where it landed and was met by law enforcement officials, the NORAD said.

No other details of the incident were made available.

The episode marked the second time in less than seven hours that fighter jets were despatched to intercept an intruder in the airspace over Camp David.

According to NORAD, the first interception was carried out at approximately 12:17 pm (1617 GMT). The plane was out of radio communication. The type of the first intruding aircraft was not disclosed.

Last Saturday, NORAD intercepted without incident a small passenger plane flying near Camp David, where President Barack Obama was relaxing, US military officials said.