Several powerful earthquakes hit near the coast of New Zealand on Thursday night and Friday morning, prompting tsunami warnings for New Zealand and tsunami watches for Hawaii.

The most powerful was an 8.1 quake that hit some 620 miles northeast of New Zealand on Friday morning, the U.S. Geological Survey said. Two earlier quakes registered magnitude 7.4 and magnitude 7.3.

There were no immediate reports of serious damage or casualties.

While the quakes triggered warning systems and caused traffic jams and some chaos in New Zealand as people scrambled to get to higher ground, they did not appear to pose a widespread threat to lives or major infrastructure.

Following the 8.1 quake, civil defense authorities in New Zealand told people in certain areas on the East Coast of the North Island on Friday morning that they should move immediately to higher ground and not stay in their homes. They said a damaging tsunami was possible.

New Zealand’s National Emergency Management Agency tweeted, “People near coast from the BAY OF ISLANDS to WHANGAREI, from MATATA to TOLAGA BAY, and GREAT BARRIER ISLAND must MOVE IMMEDIATELY to nearest high ground, out of all tsunami evacuation zones, or as far inland as possible,” they wrote.

“Hope everyone is ok out there,” New Zealand Prime Minister Jacinda Ardern wrote on Facebook.