The participation of 150 North Korean athletes competing in 14 sports is drawing special attention in Incheon because of enduring tensions on the divided peninsula dating from the 1950-1953 Korean War that ended in a ceasefire rather than a peace treaty.
South Korea bans open displays of the North Korean flag, but has made an exception for official Asian Games venues. As at the men's opening match a day earlier, the North Korean women were cheered on by a small but enthusiastic contingent of local supporters on Tuesday. They responded with four goals in the first half and another from the penalty spot in a 5-0 win over Vietnam.
The North Korean women won the Asian Games football gold medal in 2002 and 2006, and took silver in 2010, and are again among the favourites for the title.
They are competing in the Asiad despite having been excluded from next year's World Cup in Canada after five players tested positive for banned substances at the 2011 World Cup in Germany. As part of the punishment, North Korea's football federation was also fined $400,000 and a six-year ban was imposed on the team's doctor, who claimed he had merely treated the players with a traditional Chinese remedy derived from musk deer after they were struck by lightning during training.
Earlier Tuesday, South Korean police said they were investigating an official from Iran's Asian Games delegation over suspicions he sexually harassed a female volunteer at a football stadium on Monday. The Iranian man has been banned from leaving the country, police inspector Park Min-joo said.
An Asian Games organizing committee spokesman Committee said the suspect was a 38-year-old equipment manager for Iran's football team.
Athletes from the Far East to the Middle East are competing in 42 sports at the Asian Games, a key testing ground for many of them ahead of the 2016 Olympics in Rio. China has sent the largest contingent of nearly 900 athletes and is again expected to top the medal standings.
Japan had an official flag raising ceremony in the athletes' village, where team official Naoki Hagiwara said the competition would provide important experience for the nation's young athletes beyond Brazil to the 2020 Olympics in Tokyo.
"We are hoping for them to gain experience and become comfortable, when it is our turn to host they will be ready," Hagiwara said.
Regional politics shadow a number of rivalries at the games. In the latest reminder of ongoing frictions between Seoul and Pyongyang, North Korea demanded the South prevent activists from launching balloons carrying anti-Pyongyang leaflets across their border. The North said that was a precondition for high-level talks to discuss resuming reunions of families divided by the Korean War.
The Koreas last had a high-level meeting in February. Since then, North Korea has conducted an unusually large number of missile and artillery tests in what analysts see as an attempt to pressure the South.
A South Korean government official said it would take no action to block the anti-Pyongyang activists.
North Korea had already cancelled plans to send its popular cheerleaders to the games in protest at what it termed the South's hostile attitude. That was a major disappointment for Incheon organizers, who'd hoped the presence of the squad performing synchronized cheers would boost crowds.
But lagging ticket sales have added to concerns about Incheon's ability to foot the nearly US$2 billion cost of the games.
Organizers say that, excluding the opening and closing ceremonies, only 18 per cent of the tickets for the competitions have been sold. However, organizers hope to bulk up those numbers with purchases by companies and schools.
Incheon, South Korea's third largest city and home to one of the world's busiest international airports, built 17 new venues for the event, including the nearly 62,000-seat main stadium.
The games are also doubling as a rehearsal of sorts for the 2018 Winter Olympics at the South Korean ski resort town of Pyeongchang.
Associated Press writer Kim Tong-hyung contributed to this report from Seoul, South Korea.