Chinese police have detained six more suspects involved in the contaminated milk scandal that had caused deaths and kidney stones of babies.

The six, suspected of producing and selling the chemical melamine, were detained in Hohhot, capital of Inner Mongolia Autonomous Region in north China, the country's key milk production base, the municipal government said on Sunday in a notice.

It said the arrests were made during a thorough investigation in Yili and Mengniu, China's two major milk producers based in Inner Mongolia.

Tian Min, vice secretary general of the municipal government, said no more information was available so far and the police were interrogating the suspects.

He told Xinhua that investigation results are expected to be released in four to five days.

The dairy giant Sanlu based in the Hebei provincial capital Shijiazhuang in north China was the first company exposed in the tainted milk powder scandal. Many other milk products of various companies including Yili and Mengniu were later found being tainted by melamine, an industrial chemical that could make milk appear richer in protein than it actually is.

The tainted milk is known to have killed four babies and left 13,000 others hospitalized with kidney problems in China.

(Xinhua News Agency October 6, 2008)