Seven people have been killed and four others remain missing as typhoon Koppu slammed its way into south China's Guangdong Province, local authorities updated the death toll Thursday morning.

Three people in Chuanbu Township in Luoding City and four in Sihe Town of Xinyi City were killed and four others in Xinyi were missing by Wednesday night.

All of the four in Sihe town were suffocated to death after being buried by mountain mud. Of them, two were local villagers including a father and a son, and the other two were migrant workers from the neighboring Yunnan Province.

The typhoon, the 15th this year, has brought heavy rains to the province. Although it relieved the lingering drought in north and east Guangdong, the rain was also causing disruption.

Houses in Yangchun, Xinyi and Luoding cities had been destroyed by typhoon-triggered landslides, the news release said.

At Gaolan Harbor in Zhuhai City, Agios Dimitrios 1, a Panama-registered cargo ship went aground in typhoon Koppu. Fifty tonnes of fuel oil reportedly spilt in the sea area.

According to Guangdong maritime authorities, as of 8 p.m. Wednesday, the spill has been basically under control. Spill containment boom was used to prevent the floating fuel from spreading to nearby aquacultural areas.