File photo of CPU chips from Japan computer giant Fujitsu. A Fujitsu computer system run by about 200 Japanese local governments has been hit by a series of cyber attacks and is in a vulnerable condition, the company said Thursday.

A Fujitsu computer system run by about 200 Japanese local governments has been hit by a series of cyber attacks and is in a vulnerable condition, the company said Thursday.

The online system, developed to enable local residents to request official certificates and documents on the Internet, was paralysed twice on Wednesday afternoon, a Fujitsu spokesman said.

The company, which investigated the cause of the defect, found the system had been overwhelmed by a massive flow of accesses released from abused IP addresses, Fujitsu spokesman Takashi Koto said.

After resuming the system early Thursday, however, the system froze again twice due to attacks from different foul addresses, Koto said.

"They were DoS () attacks," Koto said. "We shut down accesses from the identified IP addresses, but more cyberattacks are possible from other addresses."

The system is used by 10 prefectures, including southwestern Fukuoka, the spokesman said.

About 200 of prefectures, cities, towns and villages are linked to the system to provide public online services.