"We want to make peace inside by praying and being closer to God," said local merchant Iskak, 40, at a mosque in the village of Giwangan, on the southern outskirts of Yogyakarta, the main city in the quake zone.

"The earthquake is because God would like to give a warning to people, that it is the fault of humankind."

Others prayed under makeshift canopies in hard-hit Bantul district south of the city, as their mosques had been destroyed in the disaster.

As the call to prayer sounded across Central Java, many survivors who had spent six nights in the open were still awaiting help as trucks loaded with badly-needed supplies were ambushed en route, a disaster relief official said.

The official from the government's National Coordinating Board for Disaster Management said increasingly impatient Indonesians were resorting to "stupid acts" in the wake of last Saturday's 6.3-magnitude quake.

"If there are trucks with only civilians guarding them, then they will stop and extort bags of rice and boxes of noodles," the official told AFP on condition of anonymity.

Most of the looting incidents have taken place in Bantul, according to reports from convoy drivers and residents, the official said.

"People are not getting the goods because they never arrive," he said.

"Right now it's the people who are living near the roads who are getting all the goods. Once you go inside the villages, inside the small roads, there are places that have nothing," he said.

At least 6,234 people were killed, 46,000 injured and more than 139,000 homes destroyed in the temblor, which devastated large swathes of Central Java and Yogyakarta provinces.