A researcher estimates that about 270 tsunami-caused fires could occur across 22 prefectures in the event of a massive earthquake in the Nankai Trough off central and western Japan.

"We should consider measures to forestall oil leaks, protect evacuation facilities and prevent fires from extending," said Yu Hiroi, an associate professor at the Nagoya University Disaster Mitigation Research Center.

Such fires would be caused by flammable oils or gases leaking from damaged vehicles and storage tanks. They would be difficult to extinguish and could be widespread.

Hiroi made the estimate based on tsunami-caused fire data for the March 2011 earthquake and tsunami in the Tohoku region as well as a previous government forecast that up to 323,000 people could be killed in the potential Nankai Trough quake.

Hiroi and other researchers earlier reported that there were 159 fires across six prefectures caused by the 3/11 tsunami.

The estimated fires for the potential Nankai Trough quake include 54 in Shizuoka Prefecture, 43 in Mie, 37 in Miyazaki, 35 in Kochi, 28 in Wakayama, 20 in Oita and 16 in Ehime.

"The Nankai Trough quake is expected to cause heavy damage in areas with congested buildings," Hiroi said. "As these areas are vulnerable to tsunami-caused fires, preparatory measures must be taken."