With many pharmacies looted, people suffering from diabetes, hypertension and psychological illnesses are going without medicine.

Doctors report increasing cases of diarrhea among people drinking unclean water and worry that huge piles of garbage and tons of rotting fish and other debris along the coast have become nests of infection. A growing number of patients are getting injured as they wade through the mess.

Chile said more than a dozen of its own military and civilian field hospitals were operating on Friday. Mobile hospitals from a half-dozen other countries also were opening or about to open — an unusual situation for a country that proudly sends rescue and relief teams to the world's trouble spots.

Chile signed an operating agreement for a US field hospital on Friday, enabling 57 US military personnel to work side by side with civilian Chilean doctors in coming days to support a population of 3,000 in the town of Angol. Two US Air National Guard C-130 transport planes were en route to Chile to help deliver supplies.

Field hospitals being provided by Argentina, Brazil, Cuba, Peru, Spain and the US are meant to relieve 36 heavily damaged or destroyed Chilean hospitals, including Santiago's now-closed 522-bed Felix Bulnes Hospital. Brazil's emergency field hospital was sent to western Santiago to pick up the slack.

Powerful aftershocks on Friday forced the evacuation of an older wing of Concepcion's five-story regional hospital.