PANAMA CITY, Panama (AP) _ Authorities spent a second unsuccessful day Saturday searching for a small plane carrying 10 people they believed might have been hijacked during a flight to an area near the Colombian border.

Land, air and sea rescuers said they would resume the search for the twin-engine plane Sunday. The plane took off Friday from Panama City, headed for Puerto Obaldia, near the Panama-Colombia border and about 180 miles from the capital.

At least two police helicopters were to spend the night in the Caribbean area where air traffic controllers lost radar contact with the plane, authorities said.

Panama also asked Colombia for help in determining if the plane flew over the border.

Authorities hadn't ruled out a hijacking, since there were no reports of noise, smoke or radio transmissions to indicate the plane had crashed.

Among the passengers were two crew members and eight passengers, including four children. Two of the passengers were Colombian.

Civil aeronautics director Jaime Fabrega said the plane was about 80 miles from Puerto Obaldia when it disappeared from radar screens. It had been flying at a low altitude.

Guerrillas from Colombia's largest rebel group _ the Revolutionary Armed Forces of Colombia _ have been in the area near Puerto Obaldia. In November, Colombian guerrillas disguised as tourists stole two private helicopters nearby.