International relief efforts are under way to help Indonesia's central Java residents after Saturday's earthquake killed more than 4,000 people and injured thousands more.

Soldiers, medical workers and rescue teams are scrambling to help survivors of a 6.3-magnitude earthquake that struck the ancient city of Yogyakarta and surrounding areas early Saturday morning.

The Indonesian Red Cross says $10 million is needed with as many as 200,000 people displaced. Surgeons and medicines are in short supply.

The United States and China have offered $2 million each. Malaysia, Japan, South Korea, and Australia are among the nations sending help.

Putu Suriawan, with the Indonesian Red Cross, tells VOA the next challenge is bringing supplies in with the local airport damaged.

"From the Yogya airport, the traffic will be jammed. It is very full. It doesn't have any access and the main road is always closed," he said.

Supplies are being diverted to the airport in Solo, an hour's drive away. Officials hope to have the Yogyakarta airport reopened by Monday.

Survivors are returning to their ruined houses after spending the night outdoors out of concern for aftershocks. Others are searching for family members who were caught sleeping during the quake and are still buried beneath the rubble.

The disaster zone is not far from Mount Merapi, one of the world most active volcanoes, which has been threatening to erupt for weeks.

Officials say the quake was not related to the volcano's recent activity, but could trigger more lava flows or a full eruption.