YINCHUAN - Three people were missing after a leisure boat capsized in the Yellow River in northwest China's Ningxia Hui Autonomous Region Sunday evening, the local government said.

The 25-meter-long boat carrying seven people capsized in the Wuzhong section of the Yellow River, China's second longest waterway, at 7:23 pm, a spokesman with Wuzhong city government said.

Four people were saved in time, he said.

August is the flood season and the water level in the Ningxia section of the river has kept rising.

When the accident happened, the water flow was around 2,380 cubic meters per second, the official said.

The city government sent five rescue vessels and nearly 500 people to search for the missing passengers.

An investigation is underway.