JAKARTA, Indonesia (AP) — A series of powerful and shallow earthquakes shook a sparsely populated island chain in eastern Indonesia on Wednesday. There were no immediate reports of damage or casualties.

The U.S. Geological Survey said a magnitude 6.9 earthquake hit an area 341 kilometers (211 miles) southwest of Tual, a coastal town in Maluku province, at a depth of 10 kilometers (6.2 miles).

It was followed by another 7.0 magnitude quake in the same area and two 5.1 magnitude aftershocks, the USGS said.

Indonesia’s Meteorology, Climatology and Geophysical Agency said there was no danger of a tsunami but warned of possible aftershocks.

Villagers in the Tanimbar Islands reported strong tremors for a few minutes but there was no panic, the National Disaster Mitigation Agency’s spokesperson Abul Muhari said in a statement.

He said the epicenter of the quakes was in the Banda Sea near the Tanimbar Islands, with a population of about 127,000.

The country of more than 270 million people is frequently struck by earthquakes, volcanic eruptions and tsunamis because of its location on the arc of volcanoes and fault lines in the Pacific Basin known as the “Ring of Fire.”

In 2004, a 9.1 magnitude Indian Ocean quake set off a tsunami that killed more than 230,000 people in a dozen countries, most of them in Indonesia’s Aceh province.