HONOLULU -- Police filed felony burglary charges against six of the Native Hawaiian activists arrested in Friday night's attempted takeover at Iolani Palace.

All six posted the $5,000 bail.

Police arrested 23 Native Hawaiian activists in the illegal occupation of the palace.

The gates at Iolani Palace remained chained on Sunday. The palace was closed to visitors for a second day.

It started at about 5:30 p.m. on Friday with a phone call from a palace volunteer reporting people outside locking the gates, the executive director of Iolani Palace said.

"I saw outside of my office window that several members with red shirts with security on the back had indeed locked the gate closest to the building I was in," Iolani Palace Executive Director Kippen de Alba Chu said.

Chu contacted palace security.

"Under that scenario, we are told to lock all of the buildings to protect the contents and that's exactly what we did," he said. "The first priority is to keep out anyone trying to get in. We secure everything and we make sure our employees are safe."

The six to 10 employees did not recognize the group, but knew it was not the Hawaiian Kingdom that has occupied part of the palace grounds during the day since April. In fact, Chu said that group did not show up that day.

The people who took over call themselves the Kingdom of Hawaii Nation Ministry Trust. They are from Maui. They arrived on the Hawaii Superferry.

The group members threatened employees locked in the administrative building, Chu said.

"Our employees were scared," he said. "We didn't know what the intentions were. There was a lot of stress and tension."

Tourists took the continued closure of the palace in stride.

"Now we see it's closed, and (we are) a little bit disappointed," Netherlands visitor Klaas Kosters said. "I like to go when it's possible, but I see now it's not possible. I have to wait a long time to come back to Hawaii, because it's still expensive to travel down here."

The palace will be closed until further notice, state officials said.