TOKYO -- Rescue operations were under way at a shopping mall after a strong earthquake struck southern Japan on Tuesday.

The 7.1-magnitude quake at 4:27 p.m. Tuesday hit Kumamoto prefecture, where a pair of earthquakes a decade ago killed more than 200 people. The prefecture is also home to a Taiwan Semiconductor Manufacturing plant.

More than an hour after the quake, an apparent explosion rocked an Aeon shopping mall near the quake's epicenter. The local fire department said a second-floor section collapsed, leaving multiple people trapped inside as emergency responders worked to free them. Footage aired on public broadcaster NHK showed rescuers entering the building to search for survivors.

Prime Minister Sanae Takaichi said some people were injured in the quake without giving figures. She said she has sent government staff to the region to assess the damage.

The earthquake triggered precautionary safety protocols across major industrial sites in Kumamoto.

Taiwan Semiconductor Manufacturing, the world's largest contract chip maker, said its local subsidiary activated emergency procedures and evacuated all personnel at its Kumamoto facility. The company didn't say whether there was any damage.

Two earthquakes in April 2016 struck Kumamoto 28 hours apart. The government attributed 211 deaths to the quakes, which severely damaged Kumamoto Castle, a popular tourist destination.