JAKARTA, Indonesia (AP) — Indonesia’s rumbling Mount Lewotobi Laki Laki erupted Monday, sending a column of volcanic materials as high as 18 kilometers (11 miles) into the sky and depositing ash on villages.

Indonesia’s Geology Agency said in a statement it recorded the volcano unleashing an avalanche of searing gas clouds down its slopes during the eruption. There were no immediate reports of casualties.

The country’s volcano monitoring agency had increased the volcano’s alert status to the highest level after an eruption on June 18, and more than doubled an exclusion zone to a 7-kilometer (4.3-mile) radius since then as eruptions became more frequent.

An eruption of Mount Lewotobi Laki Laki in November killed nine people and injured dozens. It also erupted in March.

The 1,584-meter (5,197-foot) mountain is a twin volcano with Mount Lewotobi Perempuan in the district of Flores Timur.

Indonesia is an archipelago of 270 million people with frequent seismic activity. It has 120 active volcanoes and sits along the “Ring of Fire,” a horseshoe-shaped series of seismic fault lines encircling the Pacific Basin.