MOSCOW (AP) — Firefighters extinguished a massive fire aboard a docked Russian nuclear submarine Friday as some crew members remained inside, officials said, giving assurances that there was no radiation leak and the vessel’s nuclear-tipped missiles were not on board.

Military prosecutors have launched an investigation into whether safety regulations were breached. President Dmitry Medvedev summoned top Cabinet officials to report on the situation and demanded punishment for anyone found responsible.

The fire broke out Thursday at an Arctic shipyard outside the northwestern Russian city of Murmansk where the submarine Yekaterinburg was in dry-dock. The blaze, which shot orange flames high into the air through the night, was put out Friday afternoon and firefighters continued to spray the vessel with water to cool it down, Emergency Situations Minister Sergei Shoigu said.

Russian state television earlier showed the rubber-coated hull of the submarine still smoldering, with firefighters gathering around it and some standing on top to douse it with water. Most modern submarines’ outer hulls are covered with rubber to make them less noisy and more difficult for an enemy to detect.

Seven members of the submarine crew were hospitalized after inhaling poisonous carbon monoxide fumes from the fire, Shoigu said.