Police on Saturday arrested two managers of a nationwide chain of day-care centers on suspicion of negligence resulting in the death in March of a toddler placed in their care, police said.

Arrested were Masamitsu Maekawa, 53, president of Chibikko-En, and Kozue Maedomari, 37, a director of the Toyama, Toyama Prefecture-based company. The chain has about 60 day-care centers in 13 prefectures.

Police said 4-month-old Ryosuke Hojo was found unconscious March 15 at a Tokyo branch of Chibikko-En after he and an 8-month-old baby were placed in the same bed for a nap. He died early the next day at a hospital.

The older baby had apparently rolled onto Hojo's face while they were sleeping, police said.

In the police inquiry, Maekawa allegedly admitted some of the charges against him by saying he would accept responsibility if the baby died through suffocation.

Police also quoted Maedomari as saying she felt responsibility as a supervisor. Police said they suspect that at least four other children have died in their nurseries in the past 13 years.

Maekawa had only five staff to care for the 56 children aged 4 or under at the Tokyo nursery at the time of Hojo's death, according to inspectors of the Tokyo Metropolitan Government.

In 1994, a group of Chibikko-En employees notified the then Health and Welfare Ministry of alleged shortcomings in Maekawa's management of the nurseries.

The group complained of unpaid overtime wages and insufficient monitoring of children, saying only four minders had responsibility for up to 40 children in another Tokyo nursery.

They also told the ministry they were only allowed to buy four lunches for 30 children. despite receiving 11,000 yen a month from the parents and guardians.