* Syrians living in ruins, burning chairs and doors
* Roads in Lebanon washed away, electricity cut
* Worst storm in 20 years - Israel Meteorological Service
By Erika Solomon and Oliver Holmes
BEIRUT, Jan 9 (Reuters) - The worst winter storm in two decades has hit the eastern Mediterranean this week, bringing destruction and death to Syria and its neighbours who are already dealing with a refugee crisis from the country's civil war.
Opposition activists in Syria, where war has forced hundreds of thousands of people from their homes and cut off access to food, fuel and power for cities and towns, say dozens of people have died there in four days of relentless extreme weather.
At least 17 people have also died due to the storm in Lebanon, Jordan, Turkey, Israel and the Palestinian territories. Schools in some areas have been shut for days, refugee camps flooded and villages isolated by closed roads.
Meteorological agencies in Israel and Lebanon both called it the worst storm in 20 years.
Snowfall in the Syrian capital Damascus and the northern city of Aleppo did not halt the fighting between rebels and forces loyal to President Bashar al-Assad, which has killed more than 60,000 people in the past 21 months.
Abu Othman, a Syrian opposition activist in the eastern Damascus suburbs where temperatures reached minus 6 Celsius (22 Fahrenheit) on Tuesday night, said there had been no let up in street fighting and shelling, although the weather had at least halted air strikes by Assad's forces.
"Our conditions are getting worse and worse with this storm. Everyone is freezing, there is nothing to heat ourselves with. There is a growing food problem because all the rain and now snow has made road conditions very dangerous," he said, speaking over a satellite Internet connection.
In northern Syria, displaced civilians were sheltering in caves to keep dry, said Fadi Yasin, an activist from the north western Idlib province, one of the first areas where peaceful protests turned into armed rebellion.
Some of thousands of people who lost their homes in shelling or had fled fighting have moved into Syria's Dead Cities, 700 abandoned settlements from the Byzantine period, he said.
"They have taken plastic tarps and sheets to cover the frames of old buildings and have been living there but obviously it is dangerously cold to live there in a storm like this," he said. "Few people have anything like fuel for heating, and many just feel lucky to have blankets."
Families are burning doors and chairs to keep warm in the absence of fuel in Aleppo, Syria's most populous city, now largely in rebel hands, said Michal Przedalcki, from Czech charity People In Need, working in northern Syria.
"Unfortunately I think it quite likely that people will die from the severe weather conditions. Already people have not been eating enough for several months, and that exposes their bodies to more disease and infection, especially after also living through weeks of cold conditions," he said.
REFUGEE TENTS FLOODED
More than 600,000 Syrian refugees have fled to neighbouring countries exposed to the storm. Many in Lebanon and Jordan were forced to move after their tents were flooded.
In Lebanon's Bekaa Valley, a makeshift camp of around 400 people was flooded and tents were wrecked when torrents of rain surged into the area.
The Lebanese themselves are suffering, with many roads washed away. Much of Lebanon's Bekaa Valley, wedged between high mountains that separate Syria from the coast, has lost electricity and phone service, and dozens of mountain villages have been cut off from roads due to snow.
In Jordan's Zaatari camp, home to 30,000 Syrian refugees, torrential rains flooded several hundred tents and forced refugees to scramble for shelter in prefabricated caravans.
Hundreds of residents were moved to a school building and trailers after water flooded their tents and damaged belongings.
"I call upon anyone who has a conscience. We want heaters for our children. Many people have moved into caravans to shelter their children from the cold and from the flooding. The living conditions are horrible," said Um Bilal, holding a bucket to empty water from her tent.
In a makeshift camp in Qobbat Beshomra on Lebanon's Mediterranean coast, the tent that Sayyad Ali, 27, built from plastic sheeting to protect his family was scant shield against rain, wind and hail whipping in from the sea.
"It's like we've returned to ancient times," Ali said as rain pelted the tent's roof. "We're living without electricity, without water, without anything."
HAIL AND SNOW
The Israel Meteorological Service said the storm, which hardly let up since Sunday, had brought the most rainfall and the most straight days of heavy rain in 20 years. The Lebanese Meteorological Agency said that only a month of straight rain in 1992 top this weeks rainfall.
Snow was expected on Wednesday in Jerusalem, and municipal authorities ordered schools closed at noon.
Ofir Gendelman, a spokesman for Israeli Prime Minister Benjamin Netanyahu, tweeted: "Hail in Tel Aviv, 1 foot of snow expected today in Jerusalem. Lake Kinneret (the Sea of Galilee) is filling up after years of drought. Who can ask for more?"
In the Israeli-occupied West Bank, two women travelling in a Palestinian taxi in the Tulkarm area were swept away by the flood and were found dead on Wednesday morning. And in Gaza, one Palestinian died and others were wounded when a tunnel collapsed along the border with Egypt due to floods, local residents and medics said.
In Hadera, a city 45 km (28 miles) north of Tel Aviv, some 2,500 homes were without electricity. On Tuesday night rescue workers used rubber rafts to navigate flooded streets and evacuate people from flooded houses.
Turkish Airlines cancelled hundreds of flights. All schools were closed in many northern and eastern parts of Turkey as well as in Istanbul where a passenger bus skidded off an icy road into a lake in Istanbul late on Tuesday, injuring 30 passengers.
The government also issued warnings about natural gas leaks as people try to heat their homes, after 8 people died from poisoning in their sleep over the past week, a regular occurrence during cold snaps in Turkey.
Television channels and radios made frequent reminders on the issue and also called on animal-loving Turks to leave bread crumbs and wheat outside their houses to prevent animal deaths.