LOS ANGELES, May 4 (Xinhua) -- An earthquake measuring 6.9 magnitude on the Richter scale jolted the Big Island of Hawaii on Friday, the U.S. Geological Survey (USGS) said.

No casualties have been reported so far and no tsunami threat is in place, according to the authorities.

The quake struck 16 km southwest of Leilani Estates, Hawaii at 12:32 p.m. local time (2232 GMT).

The epicenter, with a depth of 5 km, was initially determined to be at 19.3702 degrees north latitude and 155.0321 degrees west longitude.

The 6.9-magnitude earthquake was the largest in Hawaii since 1975. "This is in almost exactly the same location as the deadly 1975 M 7.1 earthquake," the USGS tweeted. Two people were killed in 1975's earthquake.

Bystanders said the latest quake appeared to last about 15 seconds, sending people fleeing from buildings and community centers, local news outlet Hawaii News Now reported.

The Pacific Tsunami Warning Center said there is no tsunami threat to Hawaii following the 6.9-magnitude earthquake which came about an hour after a 5.4-magnitude earthquake. There have been hundreds of earthquakes this week in the area.

"Both the 6.9-magnitude earthquake and the 5.4-magnitude earthquake today were felt strongly. I felt the shuddering of the houses and heard loud sounds," Chen Bing, a Big Island resident told Xinhua in a telephone interview.

"I was cooking in the kitchen when the earthquake was taking place. I rushed into my 10-year-old son's room and sheltered ourselves under the table," he added.

The earthquake caused thousands of local residents to lose power for at least several hours.

The Big Island is the largest island of the Hawaiian Island chain, which is home to roughly 200,000 people and the Kilauea Volcano, one of the youngest and most active volcanoes in the world.

Several eruptions from Kilauea Volcano from Thursday night to Friday morning damaged at least two homes and forced thousands of residents to evacuate, the authorities said, reporting no casualties so far. Friday's eruption is the third eruption from the volcano in 12 hours.

Lava spatter and gas bursts erupted from the fissure for about two hours, and lava spread a short distance from the fissure, less than about 10 m, according to the Hawaiian Volcano Observatory.

The agency deployed geologists to the eruption site overnight to track additional activity that may occur, and other scientists are closely tracking the volcano's overall activity.

The eruptions forced nearly 1,500 people to flee from their homes.

"All residents of Leilani Estates and Lanipuna Gardens Subdivision are on evacuation notice," said the Hawaii County Civil Defense in a latest alert on Friday afternoon, adding that police, fire and county agencies along with the National Guard are assisting with evacuation.

An emergency water restriction is also in effect for Leilani Estates, Nanawale Estates, Kapoho and Lanipuna Gardens. According to the Hawaii County Civil Defense, all water supply customers must immediately restrict water use to health and safety needs only.

Meanwhile, Hawaii tourism officials tried to assure travelers that the impact is limited to a remote region on the east side far away from the rest of the Hawaiian Islands.

George D. Szigeti, president and CEO of the Hawaii Tourism Authority, said that the safety of residents and visitors is always the tourism industry's top priority, while adding that travelers with a trip already booked to the Hawaiian Islands or in the planning stages can be put at ease knowing their vacation experience will be unaffected.

"Travelers can enjoy their vacation experience in the Hawaiian Islands to the fullest, with the only word of caution being that they stay out of areas closed to the public for their own safety," said Szigeti in a statement on Friday.