Sendai Airport in northern Japan canceled all 92 flights scheduled to arrive or depart today after construction workers found an unexploded shell near a runway, CNN reported.
The 550-pound bomb was identified as an American-made shell from World War II, the Associated Press reported.
According to the AP:
The United States heavily bombed Japanese cities during World War II, and finding unexploded bombs is not unusual, even 67 years after Japan's surrender.
Members of the Japanese Self Defense Force worked to move the bomb, which still has a fuse, CNN reported. Officials said they hoped to reopen the airport by Wednesday, but warned that it could take a week to move the bomb or set up barriers for a controlled detonation, the AP reported.
Sendai Airport is still rebuilding following damage caused by the tsunami and earthquake that hit Japan in March 2011, according to the AP.
More from GlobalPost: Population clock shows Japanese face extinction in 1,000 years