Wang Hui , whose husband was killed in the crash, said her ageing in-laws were overcome with grief when the three of them visited his tomb in Lianjiang county, Fujian province, yesterday morning.

"We can't walk out of the shadow of losing my husband. I have been thinking of him every day and can't forget about him," Wang said.

She was so anxious about visiting her husband's burial site, she could not fall asleep. On her microblog, she wrote: "Two years have passed, grief still exists and love still exists. The only thing [to relieve me] is that our beloved baby is growing up gradually."

Wang says she does not have the heart to tell her daughter, who is now three years old, that her father is dead. She often shows the girl pictures of him, saying "father went to another place to earn money".

"She is too young," Wang said. "When she turns a bit older and has the ability to accept this kind of miserable thing, I will let her know what happened to her father."

Beijing has blamed the crash on a technical failure caused by a lightning strike. One train came to a halt on an elevated track and was struck from behind by another.

Earlier this month, former railways minister Liu Zhijun was sentenced to a suspended death sentence for corruption. The country's high-speed rail system expanded rapidly under his tenure, but the fast expansion also led to safety concerns and mismanagement, which have been blamed for contributing to the crash.

Security was tightened around the accident site yesterday to discourage survivors and the families of the dead from making some kind of public display to mark the anniversary, according to residents.

"A police officer, in his uniform, stopped me and my friend and told us that we had better not approach the bridge," said resident Terry Xie, who saw both uniformed and plain-clothes police officers at the site.

"I said we were not doing anything illegal. He said he was just following the order of keeping people away from the bridge today and he hoped we can understand his job."

Xie said there appeared to be more security on hand than last year, when he also paid a visit to the site.

"I just can't figure out what they have to fear after two years have gone by" he said.

Xiang Yuyu , whose young niece Xiang Weiyi was miraculously pulled from the wreckage, said he had been turning down a steady stream of interview requests.

The girl's parents were both killed in the crash.

"I don't want to talk about this incident any more and my family doesn't want to be disturbed," he said.

A local volunteer who often plays with the girl - who is better know as "Yiyi" - said she had been admitted to a kindergarten in Wenzhou and was expected to enter the second grade in September.

Yiyi spent three hours every afternoon in a hospital to receive rehabilitation for her injuries, the volunteer said.

Her left leg was much thinner than her right one because a lot of the muscle from her left leg had been cut off in previous operations.

"Whenever I and other people carelessly mention Yiyi's parents, her grandmother will weep," the volunteer said.