Heavy snow and unprecedented cold weather have cut off power to nearly half a million homes in northern Iran, Iran Daily reported on Tuesday. Cold weather has also reduced feed stocks to petrochemical plants and led to a drop in gas supply in some cities in the region, the report added. Iran has huge gas reserves, but it has been unable to increase production quickly enough to meet its own huge demand for fuel. Northern Iran relies heavily on gas imports from Turkmenistan, especially for heating in winter. Rescue teams have been sent to help those trapped in towns and villages in northern provinces, the director of power supplies in the Caspian Sea region was quoted as saying. Also, Iran's Islamic Revolution Guards Corps (IRGC) and its Basij Militia announced readiness for rescue and relief operations. In Mazandaran and Gilan provinces, some educational centers, including primary schools and high schools, have been closed for the third day on Tuesday. Several flights have also been cancelled in northern and western cities. Low temperatures have gripped much of Iran over the past few days.