BEIJING - Chinese investigators are still searching for the cause of at least six deaths among patients who received the same antibiotic, a deputy health minister said Thursday.

Local officials have been ordered to file daily reports on possible new victims, said Jiang Zuojun.

"We can't tell what was wrong with the drug at present," Jiang said at a news conference.

The government banned the drug, clindamycin phosphate glucose, last week after a 6-year-old girl died and dozens of people fell ill. Five more fatalities have been reported since then, and news reports say there is a possible seventh death.

Investigators have conducted tests on 10 aspects of the drug and nine have found nothing wrong, while the final test - on possible bacteria in the drug - hasn't been completed, according to Jiang.