Thousands of police armed with batons stormed an abandoned school in South Korea on Thursday to evict activists who were protesting plans to expand a U.S. military base, sparking clashes that resulted in dozens of injuries.

About 3,000 police battled with hundreds of local residents and anti-U.S. protesters in the village of Pyeongtaek, about 40 miles south of Seoul, where they had occupied the school building overnight to protest the expansion plans. Some 7,000 police stood nearby.

Some of the protesters were seen bleeding from the head. Police said the clash left at least 65 injured on both sides.

A total of 114 protesters were also detained, police said.

CountryWatch: South Korea

The operation was aimed at removing protesters from the site so the U.S. military can expand the nearby Camp Humphreys and move its entire command from the current headquarters in Yongsan Garrison in central Seoul.

Several villages on the outskirts of Pyeongtaek, a city of 360,000 people, must be razed for the base construction. The government has offered residents financial compensation to move out of their homes, but many residents have strongly objected to the plans.

"We've reached a judgment that we can no longer delay this project, considering that unless this project progresses normally, it would hurt (the country's) diplomatic trust and incur an additional financial burden," Defense Minister Yoon Kwang-ung said in a statement after the clash.

South Korea and the United States agreed in 2004 on the base relocation and consolidation plan. About 29,500 U.S. troops are stationed in South Korea to help defend it from communist North Korea. The two Koreas remain in a state of conflict as the 1950-53 Korean War ended in a truce, not a peace treaty.

About 1,000 villagers and anti-U.S. protesters had gathered at the school late Wednesday, after Yoon strongly hinted earlier in the day that the government would use force to evict protesters.

As police raided the school Thursday morning, masked protesters fought back, pommelling the officers with long bamboo sticks. Many protesters ran away after about 20 minutes of fighting.

Several protesters were seen standing atop the building, holding a placard that read, "Stop the expansion of U.S. military base in Pyeongtaek! Oppose war on the Korean Peninsula!"