Vienna, Sep 4 : The International Atomic Energy Agency (IAEA) has said that the Zaporizhzhia nuclear power plant in Ukraine has once again lost connection to its last remaining main external power line but the facility continues to supply electricity to the grid through a reserve line. The agency's experts stationed at the Zaporizhzhia plant were told by Ukrainian staff on Saturday that the facility's fourth, which is also the last still operational, 750-kilovolt power line was down. A similar incident occurred last week amid shelling on the plant, Xinhua news agency reported. The three other main external power lines were lost earlier during the Russia-Ukraine conflict, according to an IAEA statement. The plant is now relying on a reserve line, which links the facility to a nearby thermal power plant, to deliver electricity to the external grid. The reserve line can also provide backup power to the plant if needed, IAEA said. The IAEA also added that only one of the Zaporizhzhia plant's six reactors remained in operation. The IAEA Director-General Rafael Grossi said on Friday that six members of the agency's expert mission remained at the Zaporizhzhia plant, including four who will leave next week and another two who will stay there as the agency's continued presence in the longer term. According to the IAEA, the experts will "carry out detailed and continuous work to assess the physical damage to the plant's facilities, determine the functionality of the main and backup safety and security systems and evaluate the staff's working conditions, in addition to performing urgent safeguards activities on the site". The Zaporizhzhia plant, one of Europe's largest nuclear power plants, has been controlled by Russian forces since early March, but its Ukrainian staff has continued to operate it. Ukraine and Russia have traded accusations of recent strikes on the facility. /IANS