Student radicals hurling firebombs and tear-gas grenades attacked a U.S. cultural center Monday, and a riot policeman died the day after he was attacked during another protest, officials said.

Three students attacked the front of the American Cultural Center in Taegu, 155 miles southeast of Seoul, shortly before noon with three Molotov cocktails and two tear-gas bombs, a spokesman for the U.S. Information Service in Seoul said. There were no injuries, the spokesman said.Police responded to the attack with tear-gas grenades and a tear-gas gun and arrested the three attackers, who were shouting anti-American slogans when they were subdued.

The building was evacuated for about 15 minutes, and the only damage to the center was six broken windows and a slightly charred sign, the spokesman said.

The attack came on the fifth day of scattered anti-American and anti-government protests by radical students demanding an end to the U.S. military presence in South Korea and a reopening of talks with communist North Korea on reunifying the divided peninsula.

The Foreign Ministry said Monday U.S. Secretary of State George Shultz will stop over in Seoul next month on his way home from talks in Bangkok with the foreign ministers of the six-nation Association of Southeast Asian Nations.

Shultz, who said last week the violence would not disrupt his official visit to South Korea, arrives July 16 for three days of talks in the capital of Seoul with Foreign Minister Choi Kwang-soo.

The most fierce protest erupted Friday, when thousands of students attempted to march to the North Korean border to meet with communist youths and talk about reunification.

Seoul authorities banned the talks and crushed the march with a massive show of force. But students clashed with police in downtown Seoul, hurling firebombs and rocks in the crowded capital streets.

The protests began Thursday, one day before the first anniversary of a nationwide anti-government uprising that forced then President Chun Doo Hwan to permit a direct presidential election and promise other democratic reforms.