The Telica volcano in northwestern Nicaragua belched gas, ashes and rocks Saturday in a series of blasts that raised fears of a full-on eruption, authorities said.

"Five explosions of medium intensity accompanied by a volcanic tremor were registered," said First Lady Rosario Murillo, citing reports by the Nicaraguan Institute of Earth Studies.

Murillo, who is the government's chief spokesperson, said the activity had raised concerns that a volcanic eruption may be in the offing.

"We had 25 minutes of anomalous activity," she said, adding that experts were closely monitoring the activity.

Telica, which is 1,060 meters (3,478 feet) high, is located some 150 kilometers (93 miles) northwest of the capital Managua.

On Wednesday, the volcano sent up dense columns of ash after a series of explosions.