PANAMA CITY, JUNE 10 -- Violent street clashes between antigovernment protesters and riot police continued for the second day today, spreading throughout the downtown area and paralyzing business.

The disturbances were the most severe in Panama, a vital military, banking and transport center for the United States, since Gen. Manuel Antonio Noriega became Defense Forces commander four years ago.

Noriega in practice controls the government. He became the target of public wrath as a result of allegations this week by his former second-in-command, Col. Roberto Diaz Herrera, that Noriega was involved in the deaths of key public figures.

Despite the lack of any corroboration of the charges so far, political opponents of Noriega have seized the moment to lash out at him.

The broad avenues of the city center, lined with foreign banks, became a battleground where riot squads, known as the Dobermans, were pelted with rocks and debris. In many incidents the police, carrying shields and rubber truncheons, were forced to flee as emboldened protesters charged them and battered their vehicles with uprooted lampposts.

Lingering tear gas and smoke from burning cars turned the air gray above the city of 400,000. Shooting could be heard throughout the afternoon, as police fired buckshot and pepper-gas grenades at the crowds.

The National Civil Crusade, a newly formed coalition of opposition union and civic groups, including the Chamber of Commerce, declared a nationwide general strike at noon. The five major opposition parties formed a Patriotic Junta of National Resistance and ordered their members to demonstrate in the streets, blocking traffic. The grouping called for Noriega to resign.

Riot police stormed a television station and clubbed the manager, Bolivar Marques, and at least five employes. The station had been broadcasting news about the riots.

Radio Continente, one of the few stations not directly controlled by the government, went off the air at 9 a.m. when its electricity was cut off, and police hurled tear gas into its offices, according to Mayin Correa, a national legislator whose family owns the station.

The government closed schools for the rest of the week in an effort to impede opposition students from organizing. Most businesses closed.

There were no reliable estimates of the number wounded in 24 hours of clashes, but reporters witnessed numerous beatings and close-range buckshot injuries. A boy who was run over by a police truck late yesterday was reported by local radio stations to have died.

Employes at the Citibank building were evacuated during the morning because of an anonymous bomb threat.

Many bank staffers were among thousands of middle-class Panamanians who stood in the streets or honked car horns for many hours in a sign of protest against Noriega. The banking commission closed banks until Monday.

Meanwhile, in an interview at his home, Col. Diaz called on Washington to release damning information that he claimed the CIA and the Pentagon had about Noriega.

"Nobody in Panama wants to be a kamikaze hero if the United States is concealing information and protecting Noriega," he said.

Diaz said Noriega informed U.S. officials about his measures to maintain tight control over leftist movements in Panama and had permitted some violations of treaties governing the Panama Canal in order to aid U.S. military actions in Central America.

Diaz asserted these moves were Noriega's "insurance policy" to dissuade U.S. officials from revealing information about his involvement in drugs and weapons traffic in the region.

The rebellious former chief of staff, who was forced from his post by Noriega on June 1, has charged that the Defense Forces commander played a role in the 1981 death in an air crash of general Omar Torrijos, who then ruled Panama.

Diaz has further charged that Noriega "organized" the 1985 killing of Hugo Spadafora, a prominent Panamanian who was involved in guerrilla activity on both sides of the conflict in Nicaragua. Noriega and his supporters have suggested Diaz is mentally unstable and irresponsible.

Former president Nicolas Ardito Barletta confirmed one of Diaz's allegations by acknowledging he was forced out of office in the 1985 by the military. It was his first public statement about his ouster.

Diaz's followers at his house, after laying down their arms for a few hours last night, were armed again today. They complained that three Catholic priests, posted at the house in return for the arms, had not provided adequate security.

In a brief statement, Noriega said the Defense Forces "reiterate our intention to defend the constitutional order." He told a small gathering of his followers outside his barracks, "Peace is more powerful than stones. They want dead, but we will not give them dead."