The announcement that a Massachusetts company has cloned human embryos has set off protests from conservative religious and political leaders who see the reported breakthrough as a dangerous step toward human cloning, the Associated Press reported today.

But scientists at Advanced Cell Technology Inc., of Worcester, Mass., stress the technology would be used to produce cells to treat diseases, not to clone humans.

Meanwhile, several cloning experts, including a former member of Advanced Cell Technology’s ethics board, dismissed the company’s claim as “nothing but hype.” They added that the company’s findings, posted yesterday on two Internet sites, lacked any significant details, including what cells company scientists grew from the cloned embryo, the AP reported.

Federal law prohibits the use of taxpayer money to clone human beings, but Advanced Cell Technology can do as it chooses because it is a private company.

Several states, including California, have banned human cloning, and Congress is considering such a ban. But company officials insist their work gives hope to people with spinal injuries, heart disease and other ailments.

The Advanced Cell scientists describe their work as preliminary. No experiment has yet produced the coveted stem cells, master cells which can grow into all kinds of body tissues.

Critics claim such research would eventually lead to “embryo farms,” where embryos would be created solely for the purpose of making stem cells, and then destroyed.