PANGANDARAN, Indonesia (AFP) -- Indonesia has started a massive operation to clear debris from the tsunami-hit south coast of Java, as a strong earthquake rattled Sulawesi island, triggering a fresh tsunami alert.

Some 3,000 soldiers, police, local officials, volunteers and residents labored to clean up homes and streets in Java, especially in the hard-hit sleepy seaside resort town of Pangandaran, following last week's disaster.

Television reports Sunday showed masses of debris being burned in Pangandaran, as well as residents clearing up their destroyed homes and businesses.

A 7.7-magnitude undersea earthquake struck off Java on Monday, unleashing giant waves that swept away homes and businesses along the densely-populated coast, sparking memories of the devastating 2004 Asian tsunami.

The national disaster agency on Sunday revised the death toll down to 596, saying 439 people were killed in West Java province, 154 in Central Java and three in Yogyakarta.

Another 73 were still missing, more than 9,500 others injured and some 74,000 displaced following the tsunami, the agency said, without explaining why the toll had dropped by more than 50 from the previous day.

But following the release of the new toll figures, local officials said at least four more bodies had been found in and around the town.

President Susilo Bambang Yudhoyono, during a whirlwind visit to the disaster zone, on Friday ordered local authorities to speed up clearing the rubble and debris left by the receding waves.

Yudhoyono said the ruins and debris would otherwise continue to cause "psychological trauma" for the local population.

Officials said Sunday the clean-up effort was to last until August 3.

"More reinforcements have since arrived from the surrounding district, bringing the total number of soldiers involved in the clean up and search operations to over 1,000," said Wasdi bin Umri, spokesman for Ciamis district.

The spokesman told AFP that nearly 1,000 police were deployed in Ciamis to help, while the local administration had mobilized 300 personnel in addition to more than 600 volunteers.

The search for bodies and clean-up operations were also continuing in neighboring Cilacap district, with local officials "mobilizing all our effective personnel," according to district spokesman Arismunandar.

Officials were trying to reassure frightened survivors living in special camps, afraid of another tsunami, that it was safe to return home, the spokesman said.

"We are spreading the message from the meteorology office which says that the number of aftershocks have been continuously dwindling from Monday and that there was no more danger of tsunami," he said.

Meanwhile, on Sulawesi, to the northeast of Java, a 6.6-magnitude undersea quake in Tomini bay sparked a tsunami warning and prompted the governor of Gorontalo to order precautionary evacuations in coastal areas.

"I have ordered the people on the coastline, through the radio, to evacuate... I have also instructed all district heads to evacuate the people from the coast," Governor Fadel Muhammad told ElShinta radio.

There were no immediate reports of tsunamis 30 minutes after the quake struck, nor were there details on the number of people evacuated.

Police contacted in various towns along Tomini bay said people ran outside buildings when the earthquake hit, but there was no mass panic and no reports of damage or injuries.

The tsunami is just the latest in a string of natural disasters to hit Indonesia over the past two years. Some 168,000 Indonesians died in the December 2004 Indian Ocean tsunami.

Less than two months ago, Java was hit by a 6.3-magnitude quake that killed more than 5,800 people.