As rescue operations resumed at dawn, rescue chief Gen. Jose Antonio Gil said about 200 people were injured and thousands were left homeless after Friday's quakes.
Radio stations in Bolivia's largest cities were broadcasting urgent requests for medical supplies, including medicines, beds and wheelchairs. They also asked for donations of blankets, food and caskets.
Trucks rushed supplies to the thousands left homeless they could reach.
Dozens of people remained trapped under rubble. About 30,000 people, mostly Quechua Indian farmers, live in the stricken area, 300 miles east of La Paz, the capital.
"I've seen bodies in the streets," President Hugo Banzer said after touring the area. "I've talked to mothers who lost their children, to children who lost their mothers and to people who are still in panic."
The government declared a state of catastrophe and set up a $5.5 million emergency fund to aid the victims and begin reconstruction.
A magnitude-5.9 quake struck at 12:36 a.m. near Aiquile, a town of 5,000 in central Carrasco province. The San Calixto Observatory said a second quake hit the same region 13 minutes later with a magnitude of 6.8. The epicenter was 55 miles below the Earth's surface.
Repeated aftershocks up to 150 in the first 12 hours followed the initial earthquake and sent panicked residents fleeing any buildings left intact.
Jose David Molina, a resident of Aiquile, the town nearest the quake's epicenter, said he felt his house shake twice and rushed to the door.
"Part of the church towers fell on my house. My wife was buried and killed," said Molina, who was being treated for minor injuries in a hospital in Cochabamba, 150 miles from Aiquile.
Molina said one of his three children appeared to have a broken neck.
Banzer said dozens of injured people have been evacuated, but the lack of electric power interrupted the rescue operations.
Army paratroopers swooped in to help, including five U.S. Special Forces commandos in Bolivia on a training mission.
Helicopters flew in emergency supplies of food and medicine from Cochabamba. Friends and relatives jammed the main hospital at Cochabamba, trying to find loved ones among the injured.
Montero said 80 percent of the houses in Aiquile were destroyed. The roof of the Aiquile hospital caved in and a landslide blocked access to the town. Tractors began clearing the rubble so rescue workers could reach more of the injured.
The quakes were felt as far away as La Paz, where some residents ran outside in panic when their buildings swayed back and forth.
Written by Peter McFarren