Authorities confiscated more than 500 pounds of cocaine after a light plane believed to be from Colombia made a forced landing during a storm, police said Saturday.

National Police press officer Vicente Ortiz said the seizure, made Tuesday, was the biggest in Salvadoran history. He said several people were under arrest, but he refused to provide their names.The daily El Diario de Hoy, citing police sources, said six Salvadorans and one Colombian were arrested.

It said the plane's Colombian pilot landed the single-enging Cessna during a storm Tuesday on a strip on a farm 40 miles west of San Salvador.

Police said the pilot, hampered by poor visibility, knocked down electrical wires as he came in for a landing.