MUMBAI, India—Some might see the towering billboards that rise out of a centuries-old Mumbai funeral ground as a message from beyond the grave.

But the signs — which exhort motorists to "Rev up your night life" by buying a popular car — have bitterly divided the city's Parsi community since they were erected last week, with many people saying they desecrate the sanctity of the place.

Trustees of the funeral ground, who authorized the billboards, say they are needed to raise cash to maintain the Tower of Silence where Parsis, followers of the Bronze Age Persian prophet Zarathustra, or Zoroaster, have wrapped their dead in white muslin and left them to be devoured by vultures since 1673.

Parsis, also known as Zoroastrians, worship fire and believe that cremation is a mortal sin and that burial pollutes the earth. So they leave their dead atop the towers to be devoured by vultures, a process they believe releases the deceased's spirit.

"I have told people who are objecting, bring me 3,000,000 rupees ($73,000) a year and I will stop the advertisements," said Burjor Antia, a trustee with the Bombay Parsi Panchayat, or council governing the community's affairs.

"But nobody brings the money," he said today.

Antia said the money is needed to maintain the lush 55-acre cemetery that begins at Mumbai's posh Kemps Corner area and spreads across Malabar Hill, the city's wealthiest neighborhood.

"We are not profiting from this; it is proper utilization of land," he said, adding that the billboards should not offend people because they are near the ground's entrance and not near the "dhokma," or towers, in which the dead are placed.

But this has not mollified members of the community, who say it is wrong to profit from the sacred ground where they believe the dead lie waiting for their souls to be freed.

"I am very, very upset. How can you commercialize a heritage ground that has existed for more than 300 years?" Anahita Pundole said.

"I am enraged that this is being allowed. This is a sanctum sanctorum for the dead and it is being destroyed," she said, using the Latin for "a sacred place."

Zoroastrianism is a monotheistic religion that predates Christianity and Islam and is believed to have influenced those faiths — and Judaism as well. It was founded in ancient Persia about 3,000 years ago, according to some scholarly estimates.

Zoroastrians once numbered in the millions, but were persecuted and forced to convert after Muslims rose to power in Iran around the mid-seventh century. A small number fled to India and their descendants became known as Parsis.

According to some estimates, there are only about 150,000 Zoroastrians in the world today.