Chileans spoke of a night of terror yesterday after being violently shaken hours before dawn by a massive 8.8-magnitude earthquake that has killed at least 147 people, and triggered a tsunami.

"It was the worst experience of my life," said 22-year-old Sebastian, standing outside his house in eastern Santiago, where residents fled their homes in panic after the quake shook the ground for almost two minutes.

"Is everybody all right?" neighbours asked each other amid tears of disbelief, as families scrambled to call and check on their loved ones. Immediate power outages made a desperate situation worse after the quake snapped powerlines.

"It was scary! Plaster began falling from the ceiling. My dogs freaked out," said UN demography expert Maren Andrea Jimenez, an American who has lived in Santiago for nearly three years.

Awoken residents joined hundreds of revellers spilling out from bars onto the streets of central Santiago, she said.

"I ran out and found everyone was totally drunk. Friends who were at clubs said it was pandemonium," Jimenez said.

"The whole time, the ground has been rumbling."

US authorities reported some 34 aftershocks have shaken Santiago since the earthquake hit.

Most houses in the capital, some 325 km northeast of the epicentre, appeared relatively undamaged from the outside, but the interior of many buildings showed evidence of the violent impact, with toppled appliances, shaken belongings and cracks ripping up walls.