KUMAMOTO, Japan, April 18 (UPI) -- The death toll has risen to 42 people after three quakes rocked southern Japan late last week, on the southwestern island of Kyushu.
The tremors struck the Kumamoto prefecture within little more than 24 hours: a 6.5-magnitude late Thursday, a 5.3 early Saturday and a 7.4 later Saturday. The first quake left up to 10 people dead in what seismologists now believe was a foreshock leading up to Saturday's temblors.
A total of 478 tremors have been recorded since Thursday, the Meteorological Agency said.
Up to 11 eleven people are known to be missing with many more possibly buried in the rubble in the region. Some people have returned home, but about 110,000 remain displaced in 100 evacuation shelters, with the government working to get food and blankets to residents.
There were about 250,000 without water, 100,000 without gas and 39,000 without power in Kumamoto.
About 30,000 rescue workers, including 20,000 troops traveled to the region to help local firefighters and police in search and rescue efforts. They reportedly arrived Saturday morning.
Rescue efforts are being hampered by heavy rain in the region, which has already experienced significant mudslides as a result of the seismic activity.
Tsunami warnings were initially issued after the quakes, but were later lifted.
Japan's Chief Cabinet Secretary Yoshihide Suga said the damage caused by the earthquakes was substantial.
Seismic activity is commonplace in Japan and much of the Asian Pacific Rim, which is positioned on the so-called geologic "Ring of Fire," where subterranean tectonic plates converge.
Eric DuVall, Marilyn Malara and Doug G. Ware contributed to this report.