Once completed in 2014, navy base in Gangjeong on the coast of southern Jeju island, would host some 20 warships . - AFP (File Photo

SEOUL: More than 1,000 South Korean riot police Friday dispersed or arrested scores of protesters who for months have blocked construction of a naval base on a scenic holiday island.

Navy engineers resumed work after police evicted about 130 protesters who have occupied the site at Gangjeong on the coast of southern Jeju Island since June.

Military officials say the dollar 970 million project is vital for national security. But village residents and activists oppose it, arguing the base could set off a regional arms race and damage the environment.

The pre-dawn raid sparked clashes but there were no immediate reports on injuries.

“Heavy equipment moved into the site after the navy erected fences to block off the protesters,” a police spokesman in Seoul told AFP.

Police detained 35 people, including three activists who have been wanted for leading violent protests for months, he said.

The operation came two days after the government warned that the project could not be delayed any longer.

The volcanic island has seen its 500,000 population sharply divided since the military in 2007 chose Gangjeong as the site for the base.

Once completed in 2014 it will host some 20 warships including submarines to help protect shipping lanes through which virtually all the country's sea trade passes.

The deployment will also help guard against sea infiltration by North Korea and could quickly respond to territorial disputes with neighbouring states, the military has said.

The island's council accepted the base, citing a survey that showed a majority of islanders support it.

But opponents ranging from environmentalists to religious leaders and anti-government activists allege South Korea bowed to pressure from the United States, which they say is eager to establish a military presence near China.

Both Seoul and Washington, which stations 28,500 troops in South Korea, deny the accusation. Seoul's defence ministry says the new base is unrelated to US calls for a regional missile defence system.