TOKYO, May 31 (Xinhua) -- Japan's industrial output increased in April from a month earlier, the government said in a report on Thursday.

According to the Ministry of Economy, Trade and Industry, factory output in Japan increased 0.3 percent in the reporting month with the ministry maintaining its basic assessment that industrial production is "picking up slowly."

The ministry said the seasonally adjusted index of output at factories and mines stood at 104.4 against the base of 100 for 2010, according to its preliminary report.

The latest figure follows a 1.4 percent increase logged in March.

The index of industrial shipments rose 1.8 percent to 103.3, the ministry said, while inventories shed 0.4 percent to 113.0.

Manufacturers in Japan believe that industrial production will increase 0.3 percent in May, but will decline 0.8 percent a month thereafter, according to the ministry's survey of manufacturers.