Chinese authorities already struggling to deal with the aftermath of Monday's massive earthquake are now trying to cope with a flood of children orphaned by the disaster.

Over the weekend more than 140 Chinese teenagers with missing parents were moved to a university campus in the Sichuan provincial capital of Chengdu.

Experts and social workers warn that much more needs to be done to repair the deep psychological damage that they and other survivors have suffered, in an earthquake whose death toll is already approaching 30,000, and is likely to climb further.

"The students have been given the food, clothes and shelter that they need since they arrived last night. And they are now starting to think about their families. They are crying at night as they can't find their parents," said their teacher Zhang Ping.

"I think we have a big problem on our hands."

Between the ages of 13 to 15, the students are from Yingxiu town, which was badly battered when the 7.9 quake rocked the southwestern province of Sichuan on Monday.

Many schools collapsed. Witnesses say they simply sank into the ground.

"The primary schools were completely flattened. My little sister is buried inside," said Luo Xiaofung, 15. "I don't think she could have survived."

"We all quickly went under our tables as our teachers told us we are considered very lucky," said Luo. Except for about 30 students and five teachers, everyone in her 1,600-strong school survived, teachers said.

SUDDEN ORPHANS

For Luo and her schoolmates, the canteen of the Chengdu Medical University will be their home for the foreseeable future.

Carpenters worked round the clock over the weekend to assemble bunk beds for the teenagers while university students removed half a dozen pool tables from the canteen to give the teenagers more space.

A large hall on an upper floor has been converted into their new dormitory with each child allotted the space of just one single mattress on the floor in the meantime.

"This is better than sleeping in a tent. It was beginning to stink (with rotting corpses) when we left Yingxiu," said another student, Zhang Li.

Most of the students busied themselves cleaning and washing their clothes and shoes during their afternoon break.

But social workers say it will be a long time before any semblance of normalcy returns to the lives of these young people -- if it happens at all.

"They may nod and agree when you tell them to be strong, but they are very hurt inside. They have lost their parents, lost everything in a flash," said social worker Qian Guijun.

"The smaller children can't even verbalise their feelings. They have a look of terror when you mention the earthquake. They just start tearing up."

Many of the students were fixated on the two large TV screens installed in their dormitory, carrying news reports of the aftermath of the quake. One child turned around and hid her face, as she quietly wiped away her tears.

Thirteen-year-old Zeng Qiang, who lost his mother in the quake and is hunting for his father, asked a Reuters journalist to contact his older sister in Beijing. "Please let her know that granny and me are alive," he said.

Yang Huijun, dean of the School of Basic Medicine, said many challenges lie ahead. Volunteers, like the Hong Kong-based Social Workers Across Borders, have approached the university to offer counselling services.

"We'll have to work on their later problems, their emotional problems, once they settle in," Yang said.