SEOUL, OCT. 31 -- Amid unusually tight security, the ruling party's presidential candidate, Roh Tae Woo, held his first major campaign rally in the South Korean capital today but failed to draw enough people to fill the medium-sized stadium where he spoke.

Roh's remarks included a rare apology for the South Korean government's record on human rights. "For human rights abuses . . . I feel responsibility, regardless of the cause, and faults should be admitted, as they are," he said.

Roh cited the torture and death of a university student in January and sexual attacks last year on a female dissident in police custody.

Today's lackluster turnout followed a provincial campaign swing in which radical protesters in Taegu and Kwangju threw firebombs, eggs and tear-gas grenades at Roh, a former general.

The pro-Roh crowds in Kwangju, a center of antigovernment sentiment, were sparse and low-key, while the turnout in Taegu, Roh's home town and a bastion of government support, was respectable but far from overwhelming.

The issue of campaign crowd sizes and reactions is of unusual importance in South Korea, which in December will hold its first direct presidential election since 1971. Publication of public opinion polls on the candidates -- Roh from the ruling party, Kim Dae Jung and Kim Young Sam from the center-left, and Kim Jong Pil from the right -- is banned. With the conventional avenue for gauging popularity closed, crowds have become an alternative measure.

Roh and his aides reject suggestions that the recent spate of hostile incidents, combined with the modest crowds he has generally drawn, indicate a failure to rouse popular enthusiasm. Officials of the ruling Democratic Justice Party point out that the number of protesters at Roh's appearances is dwarfed by the overall turnouts.

Roh, who has not held a mass open-air rally, repeatedly has said that such large-scale events should be avoided because they can whip up harmful emotions, such as regional rivalries.

Party aides also contend that the extraordinary security net around Roh has turned some supporters away. About 7,000 police reportedly were on hand for Roh's brief parade and rally in the Hyochang Stadium today. Side streets were sealed off by riot police, while Roh's open-backed jeep was almost lost in a swarm of plainclothes officers.

"Just because there are empty seats doesn't mean a lack of eagerness from the crowd," a Roh aide said.

The South Korean press, which seems intoxicated by the new spectacle of democratic rallies, exaggerates crowd estimates for all of the candidates. This may be partly due to bloated figures put out by campaign officials, who appear to suffer from double or triple vision when they judge crowd sizes.

One evening newspaper said today that 60,000 people were on hand for Roh's rally, while another daily put the figure at 100,000. A top official of Roh's party was quoted as saying 200,000 people turned out. Independent western observers agreed that there were no more than 30,000 seats in the stadium, and at the start of the rally about 10 percent of them were vacant. At least a quarter of the people left during Roh's speech.

The Hyochang rally was Roh's first in Seoul, and observers said it was surprising that he failed to draw a larger or more attentive following. Although all of the candidates come from outside of Seoul, the capital holds one-quarter of the country's population and will probably decide who wins the election. None of the Kims has yet held a major rally in Seoul.

Roh's opposition rivals brought out much larger crowds today. Kim Young Sam drew more than 100,000 people in Inchon, according to reports by western news agencies. Kim Dae Jung, speaking in Chonju, which is near his home region, also drew more than 100,000 people, according to the same reports.

In Roh's home town of Taegu, an indoor arena holding about 15,000 people was filled last week with flag-waving fans, and a parade route through the industrial city was lined with tens of thousands of supporters. It was a good turnout, but it was not a match for the hundreds of thousands of nearly delirious supporters who greeted the two Kims in their home town rallies.