Emergency teams delivered water and food and set up emergency tents in dusty towns in northern Chile on Thursday as aftershocks shook nerves a day after a powerful earthquake killed two people and injured more than 100.

President Michelle Bachelet and four government ministers traveled to the country's mining capital Antofagasta early in the day and were to go to the small towns of Tocopilla and Maria Elena, where homes and large buildings collapsed.

The 7.7-magnitude earthquake in mineral-rich northern Chile on Wednesday cut power to some of the world's largest copper mines, forcing them to work on backup generators on Thursday.

Copper prices jumped on Wednesday by as much as 6.29 percent to $3.3040 a pound on the New York Mercantile Exchange's COMEX division. That price backed off 4.11 percent in early trade on Thursday.

Power was still out on Thursday at Escondida, the world's largest copper mine.

Chilean government spokesman Ricardo Lagos Weber said on Thursday at least 15,000 people were homeless as buildings crumbled in the smaller towns along Chile's Pacific coast.

We have significant damages in Tocopilla and Maria Elena as well as in other smaller towns, Lagos said of the two hardest-hit towns.

The tremor was felt in neighboring Peru and Bolivia, as well as the Chilean capital of Santiago. Both of the deaths caused by the quake occurred in Tocopilla, 75 miles north of Antofagasta, where people were caught under rubble from crumbling roofs and balconies and where two floors of a hospital collapsed.

Electricity, water and telecommunications were cut to the town and most residents spent Wednesday night asleep outdoors, under cold desert skies.

People here are pretty afraid. There have been so many aftershocks that start with a big noise, a humming noise, and then the ground starts moving and people start to run away, Paula Saez, an aid worker for the nongovernmental organization World Vision International, said from Tocopilla.

At least 115 people were injured in Tocopilla.

An 88-year-old woman was killed when a wall fell on her and authorities said a 54-year-old woman also died, although the cause of her death was not clear.

(Additional reporting by Pav Jordan; Writing by Pav Jordan; Editing by Bill Trott)