SAN SALVADOR, El Salvador — Authorities in El Salvador evacuated an area around the Chaparrastique volcano after the peak shot a cloud of gas and ash about 3 miles  into the air on Sunday.

Civil Defense Director Jorge Melendez said a yellow alert had been issued and investigators had been sent to the area to look for signs of fresh lava, but that none has been detected so far.

"We have implemented emergency measures to evacuate villages located within 3 kilometers of the volcano," Melendez said. Shelters have been set up for the evacuees, but Melendez said some inhabitants had been loath to leave their homes. "One has to leave for one's own safety," he said.

Assistant Health Minister Eduardo Espinoza said two people had been treated at hospitals for respiratory problems apparently linked to the eruption, "but we do not have any serious cases to report."

"We are providing assistance to people evacuating, and we are asking them to protect themselves against the gases, which can affect the respiratory tract," Espinoza said. He also urged those near the volcano to avoid drinking from local water sources.

The 7,025-foot (2,129-meter) volcano is located about 90 miles (145 kilometers) east of San Salvador, the capital. Its last significant eruption was in 1976.

San Miguel is one of the country's largest cities and is located 30 miles (50 kilometers) from the volcano.