Calangute police arrested the accused, identified as Philip Fernandes, for murdering his 9-year-old son Elijha and daughter Catherine (3), Police Inspector Tushar Vernekar said.
The injured wife has been admitted to Goa Medical College and Hospital in a critical condition, he said.
The accused is an Indian while his wife, whose name has not been disclosed, is a Belarusian national, Vernekar said.
The motive behind the murder is being investigated. We can't disclose more details at this point," the Inspector said.