About 230 small earthquakes shook the upper East Rift Zone of Kilauea Volcano beginning early this morning, prompting officials to close off most of the Hawaii Volcanoes National Park as a precaution to protect visitors.

Scientists from the Hawaiian Volcano Observatory have been monitoring the situation closely since the swarm of earthquakes began around 2:15 a.m. As of 4:30 a.m., nearby residents felt the rumble with 10 of the earthquakes reaching a magnitude greater than 3.

"We're on alert," said Mardie Lane, park ranger for Hawaii Volcanoes National Park. "This is definitely something new and intriguing. We're all just watching."

Most earthquakes were too small to locate and occurred between Pauahi and Makaopuhi craters, according to the observatory Web site. Cracks in the Chain of Craters road near the Mauna Ulu turnoff opened about two centimeters.

Scientists also confirmed that lava is still flowing at Pu'u O'o.

The biggest earthquakes were 3.8 - enough to shock nearby residents but not large enough to trigger a tsunami warning, said Barry Hirshon, geophysicist with the Pacific Tsunami Warning Center.

Hirshon said they have also been monitoring the earthquakes and will issue a warning if it reaches 6.9. While there's no danger of a tsunami yet, he warns people to stay away from the water and off the fragile lava benches.

Extra rangers were called in early this morning to watch the situation, Lane said. Most of the park was shut down, including Chain of Craters road and part of the Crater Rim Drive.

Rangers evacuated 11 campers and relocated the parks' livestock of seven horses and mules to a pasture out of harm's way, Lane said.

The Kilauea Visitor Center, Jaggar Museum, Volcano House Hotel, Kilauea Military Camp, and Volcano Art Center Gallery remain open.