OSAKA — Inquiries for Osaka office facilities by Tokyo firms seeking to evacuate employees were reportedly up sharply Thursday, as companies including casual wear store H&M close up shop in Kanto and move to Osaka, while some foreign airlines were also rerouting Tokyo flights to Kansai airport.

But how long the shift from Tokyo to the Osaka region lasts is unclear, given uncertainties about radiation emitted from the Fukushima No. 1 nuclear plant and how long electricity blackouts will continue.

Kansai media, quoting local real estate agents, said inquiries from Osaka-based tenants about temporary offices for their Tokyo branches had risen sharply since Wednesday. Office space in Osaka last year was about 15 to 20 percent less expensive than Tokyo, and the presence of Kansai and Itami airports was attracting inquiries from both domestic and foreign firms, local media said.