A plane carrying U.S. Ambassador Arthur Davis flew to an American air base because armed Panamanian agents harassed his security detail at a commercial airport, a U.S. Embassy official said.

The private plane carrying Davis and members of his family landed briefly at the commercial airport, then departed after the confrontation was reported by the security detail awaiting his arrival, the official said.Davis did not leave the aircraft while it was at the commercial airport. The embassy official, Terrence Kneebone, did not say precisely what the Panamanian agents did, and there was no immediate comment from Panamanian government officials.

Long lines formed outside banks early Monday as people waited to make limited withdrawals from their accounts for the first time in more than nine weeks. Some customers said they had waited for more than two hours before the banks opened Mondaymorning.

A government order shut down banks March 3 following a run on savings by panicky depositors and the imposition of U.S. economic sanctions in an effort to force Gen. Manuel Antonio Noriega to resign as chief of the Defense Forces.

Bankers and government officials agreed to reopen after negotiations.

Noriega, the power behind the government, was indicted in the United States in February on drug trafficking charges. The general has denied the charges and said they are politically motivated.

The sanctions, including the freezing of an estimated $50 million of government funds in U.S. accounts, helped produce a severe cash shortage in Panama, which uses the U.S. dollar as its currency.

Davis and family members were returning from a day trip to the Pacific Coast island of Contadora when the plane approached Paitilla Airport in Panama City. As the small jet landed, Davis saw several Panamanian security agents armed with rifles "harassing" his security detail, Kneebone said.

U.S. security officials were in contact with the plane by radio as it prepared to land, Kneebone said, and spoke with Davis on the ground. Davis decided to fly elsewhere because of the Panamanian agents' "fairly hostile actions," Kneebone said. The plane then requested and received takeoff clearance from the airport tower before flying on to Howard Air Base, five miles northwest in the former Panama Canal zone.

One of the Panamanian security agents at Paitilla Airport demanded to know who was on the plane with Davis, said Kneebone.

It was not immediately known who was the owner of the private aircraft.

It was the second incident in which Panamanian security agents apparently sought to interfere with the ambassador's movements in Panama. On April 3, a military vehicle unsuccessfully tried to stop Davis' chauffer-driven limousine as he was leaving the residence of the Vatican ambassador.