By Helen Regan, Isaac Yee, Masrur Jamaluddin, CNN (CNN) — A volcanic eruption killed three people and triggered a rescue operation to get more than a dozen hikers stranded near the crater of Indonesia’s Mount Dukono to safety on Friday, officials said. Singapore nationals and an Indonesian citizen were among those killed when the volcano, on the island of Halmahera in North Maluku province, erupted, according to the island’s police chief and search and rescue officials.