Aid organizations and foreign governments are providing field hospitals and medical care for those injured in Central Java's devastating quake. The U.S. Marines and Navy are among those who have rushed to provide help. Doctors are now focusing on infections and complications from unattended wounds.

The U.S. Marines 3rd Expeditionary Force is looking for injured among the remains of villages shaken to rubble in Central Java's 6.3 magnitude earthquake.

A medical unit from the Expeditionary Force of 100 Navy and Marine medical and support staff stands ready to set bones, treat burns and perform surgery in a field hospital in Bantul, at the center of the quake zone. They erected medical tents in a football stadium Wednesday, but only a few patients have trickled in on their own.

Commander Carlos Godinez says the Navy doctors decided to make some house calls. Among those discovered at an overcrowded medical facility is a 25-year-old woman, Ctsiti Nuriyoni, who was crushed when a wall fell across her chest.

After several days in the open, her condition has worsened. Her baby died in the earthquake, but her husband has not yet been able to tell her. A chest tube meant to help her breathing has caused an infection. Godinez describes the problems she faces.

"Infection is a big problem here, and, when there's a fracture involved, there's always a possibility of infection of the bone, and, when that happens, it threatens the limb, and even the life of the patient. In a lot of cases, five days is really too long," he said.

More than 6,000 people died in the earthquake, which struck early Saturday. Hundreds of thousands of people were left homeless by the quake, the third major one to hit Indonesia in less than 18 months.

Although aid from around the world has begun to pour into Indonesia, including field hospitals from several countries, thousands of victims are in need of help.

Chuck Wright is the regional medical officer for the U.S. Embassy in Jakarta. He says getting medical care to patients in outlying areas is the biggest challenge facing aid organizations. But even those who make it to the hospital are not guaranteed timely care.

"Well, the system is overwhelmed," he said. "I mean, they aren't used to seeing so many people all at once, and the hospitals just can't handle it, that's why there's people we are seeing out here in the hallways and all over the place, and surgery is delayed, they are just overwhelmed."

The World Health Organization on Wednesday appealed for donations of orthopedic supplies, such as pins and surgical plates, citing a shortage of equipment and an urgent need to fix the fractures. The U.N. estimates more than 22,000 patients have been treated in 29 local and field hospitals since the quake.