Hotels in Osaka are in high demand as residents and companies leave Tokyo to seek shelter amid concerns over radiation leaks after the nation's worst earthquake.

The St. Regis Osaka, where daily room rates start at ¥70,000 this week, is fully booked for the entire week, while the banquet hall at the Swissotel Nankai Hotel was transformed into a temporary office, officials at the hotels said. All serviced apartments at Divio Osaka are occupied for this month.

Concerns over radiation leaks at the damaged Fukushima nuclear plant after the quake and tsunami on March 11 prompted workers at companies such as Blackstone Group LP and BNP Paribas SA to leave the capital.