A Japanese hospital opened the country's only anonymous drop box for unwanted infants Thursday despite government admonitions against abandoning babies.

The baby drop-off, called "Crane's Cradle," was opened by the Catholic-run Jikei Hospital in the southern city of Kumamoto as a way to discourage abortions and the abandonment of infants in unsafe public places. The hospital described it as a parent's last resort.

A small hatch on the side of the hospital allows people to drop off babies in an incubator 24 hours a day, while an alarm will notify hospital staff of the new arrival. The infants will initially be cared for by the hospital and then put up for adoption.

"We started the service but hope it won't be used," head nurse Yukiko Tajiri said. "I hope it is seen as a symbol that we are always here for parents to share their difficulty."

But government officials warned the service might only encourage more abandonments.

"In principle, parents should not abandon their babies anonymously," Prime Minister Shinzo Abe told reporters Thursday. Chief Cabinet Secretary Yasuhisa Shiozaki meanwhile said it was "fundamental for parents to raise their children with their own hands."

Similar baby drops exist in Germany and South Africa. Some US states, such as Alabama and Minnesota, also have programs protecting identities of women who give up their babies.

The drop box was set up after a series of high-profile cases in which newborn babies were abandoned in parks and supermarkets, triggering a public outcry.

Abortion is readily available and widespread in Japan where restriction against the measure is loose and there are no clear religious taboos.

Nearly 290,000 abortions were reported in 2005, according to the Health Ministry.