(CNN) -- A strong earthquake struck northern Myanmar on Sunday, killing at least 13 people and injuring 40, according to an aid agency.
The epicenter of the 6.8-magnitude quake was centered 52 kilometers (32 miles) north-northeast of the town of Shwebo in the Sagaing region, the U.S. Geological Survey reported.
Six people died in the Sint Ku township when a gold mine, a monastery and a house collapsed, according to the aid agency Save the Children, which operates inside the country. Part of a primary school also collapsed, though no injuries were reported, it said.
Two others were killed in a nearby township when a monastery crumbled, Save the Children said.
Close to the epicenter, a bridge under construction gave way, killing four workers, according to the agency.
At least one person was killed and ten were injured in the country's second largest city Mandalay, about 120 kilometers (80 miles) from the epicenter, the charity said. The quake damaged buildings, cracking walls, and knocking over pagodas, it said.
Shopping districts were temporarily closed in Mandalay, and authorities were inspecting public buildings for damage, local journalists said.
Two 5.0-magnitude aftershocks rattled the region, the USGS said. People in Mandalay remained outside of buildings after the tremors hit, according to local journalists.
In March 2011, a 6.8-magnitude earthquake struck near Myanmar's borders with China, Thailand and Laos, killing at least 75 people and injuring 111, Myanmar Radio reported.
Journalist Jimmy Toe contributed to this report