Updated

Autopsies were being performed Thursday on the bodies of five young brothers who investigators believe were slain by their mother as authorities searched for clues as to how and when the children were killed.

The bodies of the boys, ages 3 to 9, were found in their home on Wednesday after their 31-year-old mother told a doctor where they were, prosecutor Uwe Wick said. It is believed that they were killed either on Tuesday or on Wednesday, he said.

German news media have reported that the children, who lived in the tiny village of Darry in the northern Germany, were doped with pills and then suffocated with plastic bags, but Wick would not comment on the cause of death.

It was not known when the results of the autopsies would be ready.

The mother, whose name has not been released, was ordered held in psychiatric care after the grisly discovery and was to go before a judge Thursday for a ruling on a request by authorities that she be held during the investigation.

"We have requested the woman be held in a secure psychiatric facility because we assume that she represents a general danger to the public," he said.

The discovery of the dead brothers on Wednesday afternoon came the same day that authorities in eastern Germany announced they had found the bodies of three infant girls and had taken their mother into custody on manslaughter charges. The woman has denied killing the three babies.

The first body was found Nov. 27 in the eastern city of Plauen, near the Czech border, after authorities asked why the child, born in a clinic in 2002, had not yet been brought for a required checkup before starting school.

The baby girl's body was found wrapped in plastic and hidden in a suitcase in a storage area of a relative's home, police said. Two other bodies of baby girls, also wrapped in plastic, were found Tuesday in the mother's home, police said.

The 28-year-old woman, who was not been identified, was taken into custody. Her two surviving children — a baby and a child in grade school — were taken into protective custody.