Beijing traffic police said in a statement that four people had been injured when a small passenger car “brushed” several pedestrians in Haidian district, but did not say whether the act was intentional or whether it had occurred outside a school.

They said the driver had been detained and an investigation was under way. The municipal government did not immediately respond to a request for comment.

Many schools in China, a country that already has extensive surveillance systems, have increased police presence and reinforced gates since last year following a spate of similar incidents near schools and elsewhere.

Last November, an SUV ploughed into students and pedestrians outside a primary school in the southern city of Changde, injuring several people.

A week before that incident, in one of the deadliest attacks of recent years, a 62-year-old man upset with the division of assets in his divorce killed at least 35 people by ramming a car into a crowd at a sports centre in the southern city of Zhuhai.