TOKYO >> Japan has temporarily stopped using vaccines from U.S. drugmaker Pfizer Inc. and Sanofi-Aventis SA of France while it investigates the deaths of four children who were inoculated, the health ministry said Monday.

The decision to halt the vaccines against pneumonia, some types of meningitis and other infections was made Saturday. The government is hearing from experts at a meeting Tuesday, the health ministry said.

The four children, from under six months to 2 years old, died between March 2 and March 4. The deaths occurred the same day to three days after the vaccines were administered, the ministry said.

The vaccination began in Japan about a year to two years ago. The vaccines have been administered to 1 million to 1.5 million children, according to the ministry.

Pfizer in Japan said the company was cooperating with the investigation on the Prevenar vaccine. The U.S. has been using Prevenar for about 10 years, the company said.

Sanofi-Aventis in Japan said its ActHIB vaccine was approved in France in 1992, and a year later in the U.S.