Metropolitan Police Department said they confirmed two cases of suspicious calls made to elderly women in Tokyo Tuesday predending to be an official of the Japan Pension Service, according to media reports.

Police warned of possible fraud in relation to the 1.25 million cases of leaks of personal data from JPS unveiled Monday.

According to the police, two women of Minato Ward, one in her 70s and the other in her 80s, each reportedly received a call Tuesday afternoon from a man claiming to be a JPS official. The man asked for information such as the number of family members, but hung up immediately after the women tried to confirm his identity, the police said.

Meanwhile, JPS said it had received more than 158,000 inquiries and complaints on its hotline as of Tuesday. It plans to increase the number of telephone lines by 10 times to respond to the calls.

JPS said it will send a letter to those whose personal data were leaked to inform them that their pension ID numbers will be changed to avoid further damage. JPS said they will not try to contact people by phone or email.

At the same time, it notified pension offices nationwide to strengthen procedures of confirming the identity of people whose data were leaked when they visit the offices and request any changes in their personal data.