Lee Moo-young, commissioner general of the National Police Agency (NPA), said police had been put on alert since the early hours of Monday, when US and British forces began retaliatory attacks on targets in Afghanistan.
Extra police protection has been extended to US diplomatic and military missions in South Korea, those of Israel and 54 Moslem nations and the ten mosques in the country, Lee told a news conference.
"While the attacks continue, we will have to continue these measures," he said.
US diplomatic missions and military facilities in South Korea have been on heightened alert since the September 11 hijack attacks on New York and Washington. South Korea is host to 37,000 American troops.
South Korea has voiced strong support for the US-led retaliatory attacks and had earlier said it was ready to contribute noncombat troops, including medical teams and transport planes, to the allied cause.
On Tuesday, President Kim Dae-jung and opposition leader Lee Hoi-chang reaffirmed at a rare meeting that they would lead non-partisan efforts to cooperate in the US operations.
Lee Moo-young, who has led reforms to improve the NPA's performance, morale and image, said the attacks on the United States had intensified safety concerns about the 2002 World Cup soccer finals, which South Korea is co-hosting with Japan.
"We do understand these concerns and we are working hard to address them," he said, adding that America's qualification for the World Cup finals underscored the need for stiff security.
The ten World Cup arenas, 32 practice fields and 33 lodging areas in South Korea would receive protection by special troops, SWAT teams and anti-hooligan squads. Escorts would be assigned to 13 FIFA dignitaries and 800 players, the NPA said in a statement.
Additional security measures for the May 31-June 30 finals would focus on eight airports and four seaports in South Korea, which would coordinate and share immigration information with Japan, the agency said.
Lee said South Korean police had stepped up training and had received advice from counterparts in Britain and Germany on soccer hooligans. Seoul would urge foreign governments to block known hooligans from attending next year's finals.
"We have a list of the most notorious hooligans around the world and we are waiting," he said. The NPA would hold its second anti-hooliganism drill of the year this month, he added.
