* Jordan say more resources deployed to cope with rising influx
* Many towns in rural Deraa depopulated as residents flee to Jordan
By Suleiman Al-Khalidi
HAURAN PLAIN, Jordan, Feb 20 (Reuters) - Under cover of darkness, the young mother steps through the muddy olive groves on the Syrian-Jordanian border, telling her children to hold tight to avoid getting lost in the stream of people fleeing south to safety.
Her lower face covered with a white scarf, she carries a dark carrier bag while a young daughter struggles with a small suitcase containing the few possessions they were able to take from their home a few miles (kilometres) to the north.
Umm Salamah, 27, is part of a surge of refugees pouring into Jordan in recent weeks from the towns and neighbourhoods of Syria's once prosperous fertile southern agricultural lands, escaping a two-year civil war which has killed 70,000 people.
"If it had not been for my kids I would not have left Syria," says the grief-stricken woman who left behind her husband in the city of Deraa, cradle of the revolt against President Bashar al-Assad.
She was one of hundreds who crossed in a single hour one night this week at an unmarked stretch of the frontier, part of an exodus facilitated by Syrian rebels and Jordanian troops on either side of a border marked only by a broken metal and barbed wire barrier, and Jordanian sentry towers.
Before the conflict, the Jordanian forces confronted smugglers spiriting cigarettes and livestock between the two countries. Now they help elderly men and women carrying suitcases and bundles of clothes through the light drizzle.
General Hussein Rashed Zyood, commanding officer of the border troops, says over 89,000 refugees have crossed since the start of the year - more than 10,000 a week.
A total of 275,000 Syrians are either registered refugees in Jordan or awaiting registration, but the government estimates that the real refugee figure 380,000.
They are whisked by night to the frontier by Free Syrian Army rebels who now control many border areas. On the other side Jordanian army watch towers with night vision keep a close eye on Syrian troop movement.
For some refugee the crossing is a matter of just a few hundred metres' walk from a southern Syrian town to shelter in Jordan with families and tribal relatives. For others, their journey from bloodshed in Damascus and Homs takes several days.
Abu Thayer, a member of the Liwa Tawheed al-Janoub, a main rebel group in the south, said they tried to minimise the hardship of those who have taken hours to travel by foot and trucks over bumpy desert roads.
"When they reach one of the towns in our hands we provide cars that take them close to the border. They don't have to walk too long before they reach the Jordanian barbed wire," he said.
STRUGGLE WITH INFLUX
With their border ordeal over, exhausted veiled women and children huddle on the floor of a warm army tent as they wait for a quick registration process before they board large green army coaches to their new temporary shelters.
"Mama, are you done? Please can you come here?" said a young Jordanian army officer in full military gear who took the hand of an octogenarian woman as he accompanied her to the bus.
Jordan's political military establishment has made no secret of its struggle to cope with the unabated flow of refugees and the drain on the resource-poor country.
"We have had to deploy 850 soldiers and officers round the clock with 450 vehicles. This humanitarian operation has so far cost 250 million dinars ($350 million) from the armed forces budget," Zyood said.
The country's main refugee camp at Zaatari holds more than 80,000 refugees and is expected to swell even further. A new camp is expected to be open soon.
Only a few kilometres away from the Jordanian watch towers, the uninterrupted sounds of heavy shelling by mortar, artillery and tank fire across rural towns is a chilling reminder of the ongoing clashes between the Syrian army and rebels next door.
"Life in our town is no longer bearable," said a law student who gave his name as Abu Jasem. He brought his wife and seven-month-old child from Naema, a town a few kilometres to the north that used to be home to 17,000 people but is now half empty.
Forty-eight-year-old Tareq Sweidan, who owns an agricultural firm in the town of Tayba, said fierce bombardment across the countryside was accelerating the mass exodus.
"Yesterday the regime went crazy. It was not normal, the army shelled all the neighbourhoods without exception it was indiscriminate shelling," he said.
For Umm Osama, who came from Houla town in the central province of Homs - a journey that took her over 24 hours with her six year old girl Rajaa - leaving her country was a last resort. "Why would anyone leave if it weren't for the tragic conditions?" she said. (Editing by Dominic Evans and Alison Williams)