TOKYO (Kyodo) -- The Japanese government may be able to double the space available for shelters for residents to evacuate to in the event of armed attacks, if it receives cooperation from landowners, sources close to the matter said.

The estimate comes after the government carried out a nationwide survey of underground facilities that could be used to prepare such shelters. The space could expand to about 8.91 million square meters, up from the current 4.91 million, the sources said Wednesday.

In March 2024, the government classified underground shopping malls and other sites designated by local authorities as "emergency temporary evacuation facilities" capable of protecting against the blast from ballistic missile attacks.

As of April last year, the government said, it was able to secure 3,926 facilities. But the latest survey, targeting 1,741 municipalities with a view to utilizing the underground space and parking lots of large-scale commercial buildings, indicated 1,489 more could be used.