When Native Hawaiian sovereignty advocates chained shut the gates of historic Iolani Palace, they said they were reclaiming land of the Hawaiian monarchy that was stolen during the overthrow of the kingdom more than 100 years ago.

Unarmed security guards from the Hawaiian Kingdom Government group allowed only Hawaiians, media and students to enter. Tourists, employees and the general public were kept out for hours until the conflict was peacefully resolved and the palace grounds opened.

Hawaiian activists have long used Iolani Palace, the site of Queen Liliuokalani's imprisonment following the 1893 U.S. overthrow, as a prime location for protests of the United States' occupation of the islands. But never before Wednesday had they physically taken control.

"This is our seat of government and always will be," said Mahealani Kahau, who was elected "head of state" of the group seven years ago. "As long as we have breath to speak, we'll be here."

The 60 protesters began arriving early in the morning Wednesday, sealed the gates with chain-link locks and hung yellow signs stating, "Warning! No trespassing. This is private property."

Police surrounded the palace but didn't force their way inside the fence. The activists were locked out of the palace itself and didn't do any damage to the area, which they consider to be sacred.

After more than six hours, authorities and the Hawaiians agreed to end the blockade and reopen the palace to the public. No arrests were made immediately, but state officials said the protesters could still be charged. Protest leaders had said they were prepared to be arrested and would remain peaceful.

"It was kind of exciting to see an insurgency," said Dorothy Scully, a visitor from Modesto, Calif., who had a morning appointment to tour the palace but couldn't get in. "We were victims of the insurrection this morning."

The Hawaiian Kingdom Government is one of several Hawaiian sovereignty organizations in the islands, which became the 50th U.S. state in 1959. One of the most visible signs of protest seen across the state is upside-down Hawaii state flags on display at homes of members, signaling distress.

What sets this group apart from the rest is that it's the only one to establish a government headquarters, Kahau said.

"Hopefully the occupation today will make the people aware of the history of the Native Hawaiian people and the attacks on their land," said Trisha Kehaulani Watson, executive director of another Native Hawaiian group, Kakoo Oiwi.

The ornate Iolani Palace is operated as a museum of Hawaiian royalty. King Kalakaua built it in 1882, and it also served as the residence for his sister and successor, Queen Liliuokalani, the islands' last ruling monarch.

The palace's granduer was neglected after the overthrow of the Hawaiian Kingdom in 1893, but the structure was restored in the 1970s as a National Historic Landmark. It includes a gift shop and is open for school groups and offers tours for $6 to $20.

"This is the manifestation of the frustration of the Hawaiian people for the loss of sovereignty and land," said state Sen. Kalani English, a Native Hawaiian and a Democrat from East Maui-Lanai-Molokai who met with the protesters and brought them food. "This made a statement. It got the word out about the plight of the Hawaiian people."

The protesters said they wanted to restore Iolani Palace as the seat of their government, and they plan to meet there daily to conduct the business of a sovereign Hawaiian government. They pledged to return Thursday, although they say they won't restrict access to the palace again.

Kippen de Alba Chu, executive director of Iolani Palace, said the building was originally used as the royal residence of the monarchy, not as the seat of government.

Only after the overthrow of the Hawaiian kingdom was the palace renamed as an "Executive Building" to show that the old rulers were powerless, he said.

"It is historically wrong for any individual or group to state that the palace is to serve as a government building," Chu said. "We welcome any group who would like to celebrate the history of Iolani Palace and Hawaii's monarchy in a historically appropriate manner that embraces all visitors."

About 40 students from Halau Lokahi, a Hawaiian-focused charter school, later joined the activists by blowing conch shells and reciting Hawaiian chants. They came to witness the palace occupation without getting directly involved in the protest, said Hinaleimoana Wong, cultural director at the school.

"This is a crucial spot. This is where much of the injustice took place," Wong said.

The last significant conflict at Iolani Palace before Wednesday happened when sovereignty advocates clashed with flag-waving Statehood Day celebrants trying to sing "The Star-Spangled Banner" in 2006.