A Chinese court has handed down a death sentence for a man charged with the killing of a Japanese boy in southern China in September of last year.

The attacker, in his 40s, fatally stabbed the 10-year-old boy who was on his way to a Japanese school in Shenzhen, Guangdong Province. The man was detained on the spot and later indicted.

The sentencing came on Friday, the opening day of the trial.

The Japanese Foreign Ministry says the man had been charged with murder, and the court pointed out that his crime was extremely heinous and grave, and warranted capital punishment.

It noted that he bought the weapon, killed an innocent child, and phoned the media afterwards in an attempt to attract attention on the internet.

Japanese Ambassador to China Kanasugi Kenji spoke to reporters in Beijing. He said the defendant said he wanted to talk with the victim's family, the victim's lawyer and the Japanese ambassador, but otherwise there was no reference to Japan in the trial.

Japanese media outlets, including NHK, were not allowed to observe the court session. Consul-General Kijima Yoshiko in Guangdong Province was there as an observer.

In a separate case, a man in his 50s was sentenced to death on Thursday over a knife attack on a bus carrying Japanese schoolchildren in eastern China. The attack took place in the city of Suzhou, Jiangsu Province in June of last year. A female Chinese bus attendant was killed, and a Japanese woman and her child were injured.