KUNMING, Nov. 21 (Xinhua) -- Ten people were detained following a dispute between coal mine contractors which led to a deliberate explosion, killing nine people and injuring 48 others in southwestern Yunnan Province, local police said Sunday.

The explosion occurred at around 9 a.m. Thursday at a temporary shed built by the Xiaosongdi coal mine in Luxi county of Honghe Hani and Yi Autonomous Prefecture, according to local officials.

Most of the casualties, however, were said to be with Yuejin coal mine, which is at dispute with Xiaosongdi coal mine.

Local police concluded based on preliminary investigations the explosion was created by people.

According to local authorities, the contractors for Xiaosongdi mine and Yuejin coal mine, which are close to each other, reportedly had a dispute after the underground shaft of one mine broke through into the other.

Further, a spokesman with the provincial land and resources bureau said Sunday that the bureau had been investigating the dispute between the two mines and had been helping with the negotiations prior to the explosion.

Pan Mingzhou, manager of the Yuejin coal mine, said, "the two mines had no dispute at all before October, and the negotiations were going well under the supervision of the provincial land and resources bureau."

"I have no idea of why the explosion happened," Pan noted.

The detainees included Wang Jianfu, contractor of the Xiaosongdi coal mine, and Zheng Chunyun, owner of the Yuejin coal mine, said the local police.

Both of the mines have an annual production capacity of 90,000 tonnes.