A Brazilian woman was arrested Monday after a two boys, aged 10 and 3, were killed the previous day when her Jet Ski collided with their inflatable boat on the Kiso River in Gifu Prefecture, police said.

Marjori Mayumi Fugimoto, 27, from Komaki in neighboring Aichi Prefecture, said she does not have a Jet Ski license, according to police. Investigators quoted the suspect as saying that she has ridden a Jet Ski only a few times and that she "panicked" when the craft accelerated faster than expected.

Her Jet Ski allegedly plowed into the boat carrying her compatriot Fabio Akira Oishi, 35, from Kani in Gifu, and his three children, on the river in Hashima, Gifu, Sunday afternoon. It killed his sons, Hideki, 10, and Flavio, 3. Oishi and his 8-year-old daughter sustained serious injuries in the incident.