Tokyo (CNN) -- At least six people were killed when a magnitude-6.4 earthquake struck Japan Tuesday morning, a local fire department said.
The six were killed when a landslide triggered by the quake buried three homes in Iwaki, the city's fire department said. Three people were rescued and hospitalized, and fire officials were working to rescue an unknown number of others believed to be trapped, the department said.
The quake struck at about 8:08 a.m. Tuesday (7:08 p.m. Monday ET), according to the U.S. Geological Survey. It had a depth of about 13 kilometers (8 miles) and was centered about 77 miles east-southeast of Tokyo.
Monday night, one person was killed in Iwaki and several others were trapped when a powerful 6.6-magnitude earthquake triggered landslides there, the fire department said. It happened exactly one month after the country's devastating 9.0-magnitude quake and tsunami.