Dozens of Israeli firefighters began assisting their Greek counterparts on Tuesday in putting out ongoing fires that have devastated the European country. "The Greek people and the government are thankful for the friendship Israel has shown. The decision to send a delegation of firefighters won the Greek people's hearts," Ambassador to Greece Ali Yahya told The Jerusalem Post. At least 63 people have died in the past three days as Greece's worst fires in living memory obliterated swaths of forests and emptied villages, from Evros in the North to the western islands of Corfu and Kefalonia, and the Peloponnese peninsula in the South. Greece's government says it has enlisted intelligence and counterterrorism agents to foil what it sees as a deliberate plan by arsonists to destroy local forests. However, environmental experts expressed skepticism on Tuesday that arsonists were behind most of the blazes. Greece also braced for the economic impact of the wildfires, with the government budgeting nearly a third of a billion euros for immediate relief. The cost of the damage was expected to be much higher, the Finance Ministry said. Firefighting efforts were concentrating Tuesday on one front burning in the Seta area of Evia, and on the village of Matesi, near Zaharo in the western Peloponnese. Most firefighting resources would be concentrated in those two regions, with most of the firefighters that have arrived from 20 countries operating in the Peloponnese, Diamandis said. Diamandis said 18 planes and 18 helicopters - including four from Switzerland - would be used in the southern firefighting effort. "The picture we have gives us some optimism" in the south, Diamandis said. "We have a good picture and hope for some good results." Meanwhile, the 51 Israeli firefighters who arrived in Greece early Monday have been charged with keeping the fire from spreading to archeological sites near ancient Olympia. "We have received the job of getting the fire under control in a village called Kerestna, which was evacuated and has an access problem because of a huge cliff next to the village. Our cadets worked from 9 p.m. Monday until early Tuesday morning in two shifts and finally managed to control the fire," Western Galilee Fire and Rescue Service head Amir Levi told The Jerusalem Post. "This scale of fires is hard even to describe, and the eye cannot grasp the entire picture. Hundreds of villages were emptied, and people lost everything. I don't think the Mediterranean Basin has ever known fires that have taken such a heavy toll on people's lives," said Levi, who was part of the delegation. Levi added that as soon as they arrived in Greece, delegation head and Jerusalem Fire and Rescue Station commander Moshe Swissa met with local commissioners to evaluate the situation and received several assignments that mainly involved protecting evacuated sites from the flames. "The problem here is that there are so many villages and urban areas that are surrounded by forests and woods. When you finally manage to rescue one village, you lose kilometers of forests and cultivated land," Levi said. The Greek Foreign Ministry contacted its Israeli counterpart on Sunday after two days of raging fires. The delegation was ready to take off by Sunday evening, but a flight was not available until early Monday. "We sent 51 experienced firefighters, cadets from a commanding officers' course. Each one of them has at least eight years of experience in operational firefighting," Fire and Rescue Commissioner Shimon Romach, who made the decision to dispatch the delegation, told the Post. "I think that first, Israel has to take into consideration the possibility that a large-scale disaster can happen [in Israel], so it is important to keep up a good relationship with its neighbors because we would need all the help we could get if something like that happened here. No less important, it is the right, moral thing to assist a country in distress," Romach said. "Besides, firefighters enjoy a global comradeship, and whenever a firefighter comes to a different city in a foreign country, he receives all the help and assistance he needs, so we want to maintain the tradition." Ambassador Yahya said the Greek authorities were excited and touched by the Israeli gesture. "This is a heartbreaking situation, to see the people here die and get trapped by the fires, and the government has declared a national state of emergency, but it is heartwarming to hear the Greek ministers' appreciation," Yahya said. "Israel has also prepared a delegation of 12 doctors, who are ready to fly here and land a hand whenever the Greek authorities approve it, and people from the local Jewish community have volunteered to help transport food, water and supplies to evacuees all over Greece," he added. Yahya said that the firefighters, who are supposed to leave Greece on Friday unless more aid is needed, will be thanked in an affectionate reception planned by the Greek authorities. AP contributed to this report.