A powerful magnitude-5.6 earthquake has jolted awake many residents near the New Zealand city of Christchurch, but there have been no immediate reports of serious damage or injuries.

The quake struck at 6:48 a.m. local time, according to the United States Geological survey. The epicenter was about 101 kilometers (63 miles) northwest of Christchurch on the central South Island at a depth of 10 kilometers (6.2 miles).

New Zealand earthquake monitoring agency GeoNet reported a subsequent string of smaller earthquakes.

Christchurch, on the east coast of South Island, is still rebuilding from a 2011 earthquake that destroyed much of the downtown and killed 185 people.

New Zealand is prone to earthquakes due to its location on the Pacific "Ring of Fire," an arc of volcanoes and fault lines in the Pacific Basin.