Athens, Jan 25 : An intense cold wave has gripped Greece, causing travel disruptions and power outages for several hours in many regions due to heavy snowfall, local authorities said. The government has announced widespread closures across the public and private sectors on Tuesday, reports Xinhua news agency. The Acropolis hill and the thoroughfares in the capital Athens, and even the city's southern seaside suburbs, were covered in a thick blanket of snow. Uncharacteristically, the bad weather even brought snow to several Aegean Sea islands. The Attica region, the island of Crete and many Aegean Sea islands were in "a state of special mobilization of Civil Protection", Climate Crisis and Civil Protection Minister Christos Stylianides announced. The state crisis management mechanism has been activated, citizens have been advised to avoid unnecessary travel. "We need to take all precautions to avoid casualties," Stylianides said. Travel disruptions have been reported nationwide. The snowfall temporarily paralyzed traffic on the country's highways, ships remained docked at ports and flights have been cancelled, the Greek national news agency AMNA reported. The army was mobilised to assist the Fire Brigade and police in evacuating hundreds of motorists stranded for hours on highways in the greater Athens area. Drivers were urged to use snow chains even in the centre of the Greek capital. Greek national broadcaster ERT reported that three passengers were slightly injured in a train collision. "So far we have had a few power cuts only. Tomorrow will also be a difficult day. We all will have to stay on alert," Stylianides told a press conference. In several parts of the country, schools will remain closed on Tuesday and shift to online classes. Public sector services and private companies also shifted to teleworking, as the Civil Protection warned citizens against unnecessary movement. Meteorologists said that the cold wave will start receding on Wednesday. /IANS