TOKYO -- More than 100 people have died in Japan over five months from side-effects believed to be caused by a lung cancer drug sold by British-based Astrazeneca group PLC, AFP quoted the Health Ministry as saying Wednesday.

The ministry set up a panel of medical experts to explore safer use of the red tablets, currently available only in Japan and sold under the name Iressa, after reports of more than 100 deaths, a ministry spokesman said.

Since it was made available on July 16, as many as 124 patients had died by December 13 from side-effects believed to be linked to the drug, including interstitial pneumonia, Japan Broadcasting Corp.

(NHK) and other television networks said.

Astrazeneca KK, the Japanese unit of the British pharmaceutical giant, upgraded its prescription warning to doctors on October 15.

The company chose not to halt sales of the drug, which targets inoperable or recurrent non-small cell lung cancer in advanced-stage cancer patients for whom radiation and chemotherapy did not work.

The Japanese unit is 80 percent owned by the British group, with the remainder held by Sumitomo Chemical Co. Ltd.