Ryu Matsumoto resigned Tuesday as reconstruction minister just a week into his stint after he drew flak for insulting two governors in the disaster-hit Tohoku region he was tasked to rebuild, and his exit drove Prime Minister Naoto Kan into a deeper political quagmire.

Later in the day, Tatsuo Hirano, who had served as a senior vice minister at the Cabinet Office in charge of disaster reconstruction under Matsumoto, was promoted to the post of reconstruction minister. Hirano, 57, is an Upper House member who hails from Iwate Prefecture, unlike his Kyushu predecessor.

Kan came under fresh criticism from the opposition camp as well as from within the ruling Democratic Party of Japan over Matsumoto's contentious remarks over the weekend that angered the communities ravaged by the March 11 earthquake and tsunami.