A man stabbed to death an 8-year-old boy and a 70-year-old woman on Monday afternoon near a primary school in South China's Guangxi Zhuang autonomous region, police said.

Yang Jiaqin, the knife-wielding suspect, who is around 40 years old, also injured five other people - two boys, aged 7 and 12, a 7-year-old girl and a couple in their 30s - at 4:30 pm, only 400 meters from the Xizhen Primary School in Xichang town, Hepu county, according to the police.

After the police were reported to have captured a middle-aged man, the publicity department of Beihai said the suspected murderer is a mental patient, who chased and struck out at passers-by after the school had closed.

The injured are being treated in a hospital, while the police continue their investigation.

The attack came almost three weeks after students were stabbed outside a primary school in Nanping city of East China's Fujian province.

Zheng Minsheng, 41, a former community doctor, was sentenced to death last Thursday for murdering eight pupils at the gate of the Nanping Experimental Elementary School on March 23.

The string of school attacks has prompted some provinces and municipalities to take measures to ensure the safety of students.

In a notice issued on April 4, the provincial government of Shaanxi said that local police should strengthen patrols around schools and crack down on violent crimes that target teachers and students.

The public security bureau in Beijing has also required police cars to be stationed near school gates during rush hours when students go to or depart schools.