PANAMA CITY, JUNE 15 -- Concern is increasing among U.S. officials about dozens of arrests, incidents of violence and tightening press censorship in Panama since a state of emergency was declared Thursday, according to sources here and in Washington.

Short-term arrests and street scuffles between opposition protesters and government troops continued, while a general strike called by middle-class business and civic groups collapsed in its fifth day.

The Interior Ministry announced today that no international news publications will be allowed to circulate in Panama without being reviewed first by government censors. Among the publications affected are the Miami Herald, whose international edition is printed in Panama, the International Herald Tribune and the New York Times.

A truck driver distributing 300 issues of the Miami Herald was detained for several hours by police and the papers confiscated. Four independent Panamanian news publications, including the opposition daily La Prensa, remained closed after the government imposed censorship on them Thursday.

The opposition National Civic Crusade, led by the Chamber of Commerce, called for businesses to open briefly this morning to pay employes then to close at midday. But banks and retail stores remained open in the afternoon.

U.S. Embassy officials received a flood of phone calls from Panamanians seeking American help to find detained relatives, and U.S. Ambassador Arthur Davis has intervened to secure the release of a number of detainees. The embassy has retailed three officers to review reports of rights violations.

Davis was also worried about the sudden flight Saturday of influential business magnate Gabriel Lewis Galindo, with whom he has maintained close contacts, according to a Washington source familiar with the events. Davis dined with Lewis the night before he left, the sources said.

Lewis, a former Panamanian ambassador to the United States, has said he fled Panama after receiving threats late Friday from the head of military intelligence, Col. Bernardo Barrera. He arrived in Washington today to begin lobbying on behalf of the opposition to the government controlled by military strongman Gen. Manuel Antonio Noriega.

Lewis also met lated in the week with Chamber of Commerce president Aurelio Barria and the top commander of the U.S. Southern Command, Gen. Fred Woerner, at the general's Canal Zone home, according to a source close to the events.

Barria and Lewis, the source said, informed Woerner about the National Civic Crusade's goal of forcing the dismissal of military officers, including those accused by the former Defense Forces chief of staff, Col. Roberto Diaz Herrera, of being involved in corruption and assassination.

The accusations by Diaz, who was forced to retire June 1, sparked a week of riots and opposition protests against Noriega.

Barria recounted how he was beaten and detained for several hours Thursday. Woerner's responses were "terse," the source said, and he "appeared not to want to get involved."

A spokesman for the general said: "Gen. Woerner, who returned June 6 to Panama, where he has been assigned during four of the last five years, has a lot of friends here. He will continue to see friends who call him as he has been doing this last week."

Noriega, in messages designed to mobilize his nationalist supporters, has hinted in recent days that U.S. officials were behind a what he called a "plot" by the opposition, led by Lewis, to oust President Eric Arturo Delvalle. But Noriega's public remarks about the United States remain cordial.

Over the weekend, there were reports that hundreds of demonstrators were detained. Witnesses said dozens of protesters were held in a former hotel building now controlled by the government. They said demonstrators are being detained there for as long as a day before being released or transferred to jail.