TOKYO - Japan plans to send more than 20,000 soldiers into its northern disaster zone Monday in an intensive mission to recover the bodies of those killed in last month's earthquake and tsunami.

A man walks past burning debris in an area devastated by the March 11 earthquake and tsunami, in Minamisanriku town, Miyagi prefecture, April 23, 2011. [Photo/Agencies]

More than 12,000 people are missing and presumed dead from the twin disasters that hit March 11. Some were likely swept out to sea, while others are buried under the mass of rubble. About 14,300 are confirmed dead.

Defense Ministry spokesman Ippo Maeyama said Sunday that the military would send 24,800 soldiers to carry out a two-day search of the area. Police, coast guard and US troops will also be involved.

Agriculture officials also plan to enter the evacuation zone around a stricken nuclear plant to check the fate of hundreds of thousands of animals abandoned by fleeing farmers.