China's foreign ministry spokesperson says the initial police investigation indicates Monday's knife attack at a school bus stop that wounded a Japanese woman and her child was an "isolated incident."

Mao Ning, speaking at a news conference on Tuesday, also said the incident was regrettable.

Mao said the government will continue to take effective measures to ensure the safety of all foreign nationals.

The incident took place in the eastern city of Suzhou, Jiangsu Province. A man with a knife attacked a Japanese school bus carrying students. He wounded the woman and her child, who were at the bus stop.

A Chinese bus attendant was also stabbed. She is reportedly in critical condition.

Local police disclosed the incident on Tuesday afternoon and said they detained a 52-year-old man. They said the suspect recently moved to Suzhou from another area and is unemployed. But the police gave no further details, including the motive behind the attack.

Japan's Consulate-General in Shanghai said Consul General Akamatsu Shuichi met with Suzhou Mayor Wu Qingwen on Wednesday. The Japanese mission said Akamatsu told the mayor that the incident is extremely regrettable.

Akamatsu reportedly called for the swift sharing of detailed information, including the background of the incident, and strengthened security around Japanese schools.

Earlier this month, five people, including US college instructors, were wounded in a stabbing at a park in the northeastern province of Jilin. Last October, a family member of an Israeli diplomat was stabbed and wounded in China's capital.

In both the Jilin and Beijing cases, police detained men in their 50s. But police have not disclosed the motive of either suspect.