"Terrorists are enemies of all the people in the world! May the world have peace and innocent people never be hurt," another Sina Weibo user named "Aileen_Michelle" wrote.
Robert Hill, dean of Boston University's Marsh Chapel, who visited Zhou in hospital, said she had undergone surgery on Monday and Tuesday.
"She is doing well," Hill told BU Today, the university newspaper. "She has her friends around her, and she will soon have family around her."
According to Xinhua News Agency, Zhou was still very weak on Tuesday but could speak a few words and smile.
"Zhou had abdominal injuries from the blast. She came out of the coma today and is in stable condition now," said Owen Zhang, 21, from Shenzhen, who is also studying at Boston University.
Zhang said Zhou's parents are trying to get a visa to the US to visit their daughter.
Zhang, who has lived in Boston for two years, said if he had not overslept on Monday, he would probably have been on the same block where Zhou and her two Chinese friends were when the blast occurred.
Qian said the three of them watched the marathon around noon before having lunch, and at about 2:40 pm headed for the Apple store on the same street where the explosion occurred, according to China News Service.
As runners crossed the finish line and many people were on the street, Qian lost sight of her friends when she heard the first explosion.
She rushed into the basement of the Apple store to hide with more than 10 other people, who were all frightened. They later followed store staff out of an emergency exit and onto the street.
"I felt like a bomb may fall from the sky at any moment," Qian said. She said she felt very lonely and helpless for the first time in her life, surrounded by a scared crowd, debris on the ground, and soldiers carrying guns, and holding a phone that couldn't get a signal.
Some 27,000 runners from nearly 70 countries competed in the marathon.
President Xi Jinping sent his condolences to US President Barack Obama over the tragedy. Xi expressed his deep sympathy and sincere condolences to the US government and its people over the losses and casualties caused by the bombings.
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