SANTIAGO, Chile (AP) — A powerful magnitude-8.3 earthquake last night hit off Chile’s northern coast, causing buildings to sway in Santiago and other cities and sending people running into the streets.

At least three aftershocks above magnitude-6 and other strong shakes rattled the region as tsunami alarms sounded in the port of Valparaiso in the first major quake since a powerful quake and tsunami killed hundreds in 2010 and levelled part of a southern Chilean city.

Officials ordered people to evacuate low-lying areas along the 2,400 miles (3,900 kilometres) of Chile’s Pacific shore, from Puerto Aysen in the south to Arica in the north. Cars streamed inland carrying people to higher ground.

There were no immediate reports of injuries, but authorities said some houses collapsed in the inland city of Illapel, about 175 miles (280 kilometers) north of Santiago.

Illapel’s mayor, Denis Cortes, told a local television station that electricity was out in the city. “We are very scared. Our city panicked,” he said.

The US Geological Survey initially reported the quake at a preliminary magnitude of 7.9 but quickly revised the reading upward to 8.3. US officials said the quake struck just offshore in the Pacific at 7:54 pm (6:54 pm EDT, 1154 GMT) and was centred about 141 miles (228 kilometres) north-northwest of Santiago. It said the quake was 4.8 miles (5 kilometers) below the surface.