A strong earthquake hit near New Zealand’s second-largest city, Christchurch, early Saturday.

There were no immediate reports of major damage, but Radio New Zealand described the quake as “severe” and reported that power was out across the city. Some residents posted Twitter alerts reporting damage and large aftershocks.

The quake, which was recorded at 4:35 a.m. (1:35 p.m. Friday ET), registered 7.2 on the Richter scale, the U.S. Geological Survey said in Washington. The USGS predicted only light damage based on its Modified Mercalli Intensity Scale.

Christchurch is New Zealand’s second-largest city and the largest on the nation’s southern island, with a population of about 350,000.