Updated

A powerful earthquake hit deep under the South Pacific late Tuesday north of New Zealand, and it rocked a wide area of the country, but no damage or injuries were reported.

The Pacific Tsunami Warning Center issued a bulletin saying the magnitude 7.4 quake had not generate a destructive Pacific-wide tsunami but warned it could spawn a small tsunami within 60 miles of its epicenter.

The U.S. Geological Survey said the quake hit at 10:39 p.m. (6:39 a.m. EDT) about 90 miles below the seabed, and was centered about 180 miles south-southwest of Raoul Island in the Kermadec island chain, which is 712 miles northeast of New Zealand's largest city, Auckland.

It came hours before countries around the Pacific rim were to test a tsunami warning system spanning the world's largest ocean.

Later Tuesday night, an earthquake measuring magnitude 6.8 struck western Indonesia, but no damage or casualties were reported and the quake did not appear to have triggered a tsunami.

The quake struck at 10:28 p.m. (11:28 a.m. EDT) off the coast of Nias island, just over 600 miles northwest of Indonesia's capital, Jakarta. Indoesian meteorologist Agung Sunaryadi said "some cracks were reported on land, but that's all we've heard."

The powerful quake north of New Zealand, which seismologists said registered at magnitude 7.5, rocked a wide area of the country -- but was unlikely to have caused damage, seismologist Ken Gledhill told The Associated Press.

"It has been felt very widely but is unlikely to have caused any damage in New Zealand," he said, adding that within half an hour more than 500 people had reported the quake's impact.

"It was too deep to have ruptured the sea floor," Gledhill said, adding a tsunami was unlikely "if that depth is correct."

A policeman in the east coast North Island town of Whakatane said he was sitting on a chair talking to the police communications center in the northern city of Auckland when it struck.

"Things started moving and I thought, 'this is a goodie,"' said Sgt. Andrew O'Reilly.

Wellington police inspector Peter Stokes said there were no immediate reports of injury or damage.

"We sure did feel it. Our building swayed a bit," he said.

Raoul Island was the center of a series of earthquakes during a volcanic eruption in March that killed a New Zealand Department of Conservation worker and forced the evacuation of the island.

Several conservation workers returned to the island last month to perform tasks like eradicating weeds, monitoring birds and preventing the arrival of unwanted pests such as rats.

There was no immediate word on whether they were affected by the quake.

The quake was felt as far south as Christchurch on South Island.

New Zealand is among more than two dozen countries taking part in the drill to test the Pacific warning system that has been in place since 1965.

During the exercise early Wednesday, the Pacific Tsunami Warning Center in Hawaii will send out warnings about mock earthquakes off the Chilean coast and Luzon island in the northern Philippines that are powerful enough to set off a tsunami across the vast ocean.

Governments will test if and how fast they receive the warnings and how rapidly they are relayed through domestic emergency alert systems.