SYDNEY — A small tsunami was generated off Vanuatu on Tuesday after a powerful earthquake rattled the South Pacific island nation, the Pacific Tsunami Warning Center said.

The 9-inch wave was observed off the capital Port Vila, where buildings shook and power lines were downed by the 7.5 magnitude quake.

"It was quite a significant earthquake, and we're still having a few aftershocks," Ben McKenzie of the New Zealand High Commission told The Associated Press by phone from Port Vila.

The quake hit about 25 miles northwest of Port Vila at a depth of 22 miles, the U.S. Geological Survey said.

The four-story office building housing the New Zealand High Commission suffered some damage, said McKenzie, first secretary at the New Zealand diplomatic post. Office shelves and ceiling tiles fell down and computers were "thrown across the office" by the jolt, he said.

"We're trying to ensure everybody is safe and we're evacuating the building" to check that it's not "structurally damaged," he said.

Telephone lines in Port Vila were cut by the quake, and there were several power outages, McKenzie said.