Thousands of Hindu worshippers climbed an active volcano in Indonesia on Thursday to throw offerings from crops to livestock down its smouldering crater in a centuries-old religious ceremony.

Every year people from the Tengger tribe gather from villages in the highlands around Mount Bromo to trek to its peak to cast goats, chickens, fruit, flowers and vegetables into its crater as part of the Yadnya Kasada festival.

A chain of worshippers, some lugging goats on their backs, trekked to the edge of the crater in hope of pleasing their Hindu gods while bringing prosperity and good fortune to the communities of the Tenggerese, an Indigenous group in eastern Java.

"Despite the pandemic, I still come up here every year bringing crops (to be thrown into the crater) to express gratitude to the gods and the ancestors," Wawan, one of the worshippers, told AFP.

Wawan had earlier launched offerings of chicken and crops into the volcanic cauldron while wishing for good health and fortune on top of the mountain famed for its stunning sunrise views.

Some villagers not part of the Tengger tribe stood on the crater's steep slopes armed with nets in a bid to snatch the offerings out of the air before they disappeared into the smokey void.

It is not part of the ritual, but some members of the local population have the frugal urge not to let the offerings go to waste.

Thursday's ritual was the third Yadnya Kasada ceremony since the Covid-19 pandemic hit Indonesia, but it did not deter worshippers from again carrying out their yearly sacrifice.

Bambang Suprapto, head of the area's Hindu community association, said the annual ritual had to continue as it "cannot be held in another place" or virtually.

But access to the crater during the ritual was limited to worshippers and tourists were barred in line with the government's Covid-19 guidance, he added.

The festival dates back to the 15th-century legends of the Javanese Hindu Majapahit kingdom's princess Roro Anteng and her husband.

Unable to bear children after years of marriage, the couple begged the gods for help.

Their prayers were answered and they were promised 25 children, as long as they agreed to sacrifice their youngest child by throwing him into Mount Bromo.

Legend has it their son willingly jumped into the volcano to guarantee the prosperity of the Tengger people.

The sacrifice tradition continues to this day, although the Tengger tribe sacrifices their harvest and farm animals instead of humans.

As local community chief Bambang lobbed his batch of crops into the volcanic crater, he prayed for harmonious relations between humans and God, nature, and their fellow human beings.

"If we take care of nature, it will take care of us as well," he said.