Experts with the MOH and provincial health departments had looked into 11 infant death cases since September across the country, and had ruled out connection to the tainted milk powder in five cases, the ministry said on its website.

They could not, however, rule out such possibility in the rest six cases, it said.

Four of the six cases occured in Jiangxi, Zhejiang, Guizhou and Shaanxi Provinces respectively, while the rest two cases occurred in the northwestern province of Gansu.

It did not give any further details.

Previous reports said three babies, including two in Gansu Province and one in Zhejiang Province, had already been confirmed by the ministry to have died from consuming the tainted milk from May to August.

The ministry did not make it clear whether the three confirmed cases were included in the six undecided case.

Meanwhile, 861 infants were still receiving treatment for kidney problems caused by tainted milk powder by last Thursday, the ministry said.

The figure dropped by about 200 from the previous week, when the number of hospitalized infants stood at 1,041.

All together 294,000 infants were found to have suffered from diseases of urinary systems in the ministry's nationwide screening, it said.

Among them, 154 had been in serious conditions, but were all stable by yesterday. A total of 51,900 children had been hospitalized and 51,039 had recovered and left the hospital.

Most of the sick children were found to have only sand-like stones in their urinary systems.