On Thursday, Italy's foreign ministry said it would summon India's ambassador to demand "incisive action" to prevent further attacks against Christians.
Kumar said on Friday that bodies of two Christians believed to have been killed earlier this week were found on Friday.
About 25,000 Catholic schools were due to be closed in India on Friday in a symbolic protest against the killing.
(Writing by Melanie Lee; Editing by Alistair Scrutton and Valerie Lee)