An 11-month-old boy died after being attacked by two Great Danes while in his grandfather's arms at their home in the city of Toyama, police said Saturday.

The large dogs, which are 1.2 meters long and weigh 80 kg each, bit Jin Nakamura in the head at around 5:30 p.m. Friday while he was accompanying his grandfather to the garden to fetch the dogs' feeding trays.

Jin was being held by his grandfather when the dogs attacked, according to the police. The grandfather, who is in his 50s, asked a passer-by to call an ambulance.

Jin sustained a serious head injury and died two hours later in the hospital, the police said. His grandfather sustained a leg injury while trying to fend off the dogs.

Both dogs were not leashed while in the garden, which is surrounded by a 1.8-meter metal fence.

Great Danes were originally bred for hunting but are known for being affectionate "gentle giants" as pets.