Disaster officials in Indonesia say 311 bodies have been recovered from an earthquake and tsunami near Sumatra, while more than 30 people are confirmed dead in a volcanic eruption on the island of Java.

Another 372 people are still missing after a three-meter high tsunami washed away whole villages on Monday in the remote Mentawai islands, off Sumatra's western coast.

Bad weather prevented most rescuers and relief supplies from reaching the scene until Wednesday.

Questions are being raised about whether the country's early warning system failed to alert the residents. The system was installed after the 2004 Indian Ocean tsunami which killed 230,000 people, about half of them in Indonesia's Aceh province.

About 1,300 kilometers to the east in central Java, disaster officials are examining the extent of the damage from Tuesday's eruption of Mount Merapi, Indonesia's most active volcano.

The dead include an elderly man known as the mountain's spiritual gatekeeper.

Almost 30,000 people were evacuated from the slopes of the volcano before the eruption, but many of them have lost their homes. Authorities say more eruptions are still possible.

Indonesian President Susilo Bambang Yudhoyono cut short a visit to Vietnam to oversee rescue efforts.

Indonesia straddles several fault lines that make the vast island chain vulnerable to volcanic and seismic activity.

Mount Merapi, whose name means "mountain of fire," last erupted in 2006, killing two people. A similar eruption in 1994 killed at least 60 people, and a 1930 eruption killed 1,300.