SEOUL, JUNE 20 -- Clashes between demonstrators and police continued today, with Buddhist monks taking part in an antigoverment rally for the first time since street fighting broke out 11 days ago. The monks, using their fists and umbrellas, fought police who tried to drag them away.

The protests came after a nationally televised plea for calm by Prime Minister Lee Han Key last night.

Tonight, about 10,000 students marched through downtown streets in Kwangju, scene of a bloody uprising against the government seven years ago, newspapers reported. They occupied about 300 yards of a main avenue and burned a police substation.

About 4,000 demonstrators battled riot police in 10 locations around the capital, state-run television reported tonight.

In the southern port of Pusan, South Korea's second largest city, about 4,000 students staged violent demonstrations, briefly commandeering four city buses and two oil tanker trucks and stalling midafternoon traffic until riot police fired tear-gas grenades at them.

Protests also occurred in Taegu and Chonju cities.

The demonstrations in the capital today were smaller than some that have occurred in the past 10 days.

But witnesses said riot police, perhaps reacting to the death last night of an officer in the city of Taejon, south of the capital, were more aggressive than usual in putting down today's demonstrations.

The officer's death was the first fatality since rioting began June 10.

In a busy downtown area here, about 500 students and a dozen Buddhist monks with shaved heads and in gray robes marched behind banners that said, "We shall not be deceived" and "Let's end military dictatorship."

Riot police surrounded them, and plainclothes police closed in, beating some of the students and arresting several of them.

Earlier in the afternoon, police blocked a protest rally organized by several hundred Buddhist monks at the Chogye Temple, or Temple of Royal Awakening, across the street from the headquarters of the ruling Democratic Justice Party.

Buddhists make up about a quarter of South Korea's population of 42 million. However, temples so far have not been centers for protests, and monks largely have remained aloof from the demonstrations.

More than 1,000 riot police sealed off the entrance to the temple and the street in front of it. When about 50 monks and two dozen students moved up the street toward the police, a shoving match ensued, and fighting broke out as plainclothes police started grabbing the monks. They fought back with fists and umbrellas. Police fired tear gas into the crowd and arrested several monks.

Inside the temple, one monk said the purpose of the rally was to hold a prayer meeting to "resolve the grave situation of the nation."

The U.S. undersecretary of state for security assistance, Edwin Derwinski, arrived in Seoul today for talks. Newspaper reports here, quoting government sources, also said Gaston Sigur, U.S. assistant secretary of state for East Asian and Pacific affairs, is expected to arrive here for talks Tuesday.