NTT DoCoMo Inc. has unveiled a mobile phone that features an alarm and an automatic calling function to keep children safe, as an increasing number of them fall victim to crime.

The country's largest mobile phone network operator will begin selling the new handset, the FOMA SA800i, in March for between 20,000 yen and 30,000 yen.

The third-generation phone is equipped with an alarm of about 100 decibels, which children can quickly set off in an emergency, NTT DoCoMo said.

Once the alarm is activated, the mobile phone will call up to three registered numbers at regular intervals with a voice message alert until all registered numbers pick up, or until a password is entered into the handset, making it difficult for an attacker to deactivate the alarm.

Parents who sign up for the "imadoco" search ("Where are you now?") location service, to be offered for 210 yen per month, can set their phones to automatically receive e-mail messages, updated at regular intervals, that track a child's location.

Parents can also receive an update when the handset is turned off.

Among other safety features, the battery can be secured with a special screw to prevent it from being removed.