Authorities in Iceland have downgraded the threat level from the volcano that erupted earlier this week, as officials said they could no longer observe volcanic activity at the site of the eruption. The eruption on Monday opened a fissure in the ground about 2.5 miles (4km) long, spewing orange lava into the sky only 2 miles from the town of Grindavík. “Volcanic activity seems to have come to an end late yesterday night or early that morning,” the Icelandic meteorological office (IMO) said on Friday, adding no activity had been visible during surveillance flights. “Despite that, it is possible that lava is flowing underneath ... and therefore it is not possible to say that the eruption is over,” it said. Authorities also lowered their alert level. The state of emergency, declared on Monday evening, was downgraded by a level. On Thursday, authorities began allowing the 4,000 residents of the evacuated town access to the small fishing port between 7am and 4pm. But authorities said it was still not safe for overnight stays and first responders were present in the town in case an emergency evacuation was required. Amid weeks of warnings from scientists, the authorities built reinforcements around the Svartsengi geothermal power plant, which is just over a mile from the eruption and supplies electricity and water to 30,000 people on the peninsula. Discussions are taking place about the possibility of building a similar barrier to protect Grindavík. Volcanic eruptions are common in Iceland, which has 33 active volcano systems, the highest number in Europe.