Some Chinese students who plan to start their studies in the United States next month might miss the beginning of the semester as the US visa issuance system has broken down, an overseas study insider said on Sunday.

"The number of student visa applications usually peaks in June and July, because the semester starts in late August in many US universities, and students who recently made appointments for visa application interviews will be delayed by the breakdown," said Wang Jing, director of US consultants of Chivast Education International, an overseas studying consultancy in Beijing.

"They may have to postpone their schedules, including the visa application and flight to the US," he said, adding that the number of Chinese students affected is unknown.

The US State Department's passport and visa issuance system has broken down because of a computer problem, delaying visa and passport processing since Thursday.

The system is still experiencing technical problems, according to a bulletin posted on the State Department website on Saturday.

"As of July 26, we are operating at a significantly reduced capacity and will be until we clear the document backlog. This issue is worldwide and is not specific to any particular country or visa category," the bulletin said.

"We are working urgently to correct the problem and expect the system to be fully operational again soon. We will continue to post updates to travel.state.gov as more information becomes available," it said.

"Now, little information about the breakdown has been disclosed, and nobody knows when the system will resume work. All we can do for now is wait," Wang said.

The US embassy suggests that international students start their visa applications four months before their semester begins, Wang said.

"People who applied for their visa in April, May and June have received their visas, and the incident didn't affect them," he said.

Liu Yang, a Shandong province student who will begin undergraduate studies at Worcester Polytechnic Institute in Massachusetts in late August, said he submitted his visa application materials on Jun 27 and received his visa two weeks later.

Liu graduated from Beijing National Day School's international department, where all the students later study abroad in foreign universities, and so do not take the gaokao, the national college entrance exam.

"We were told that the earlier we applied, the better. So most of my classmates who were going to study in the US handed in their visa materials in May, and very few in June, and we haven't been affected," he said.

For students who are delayed by the incident, Wang said he thinks their US schools will take measures, such as postponing the enrollment date.

The breakdown also affects tourists to the US. Gao Bei, director of tourism website lvmama.com's public relations department, said, "We tell people who are going to schedule an appointment to wait until the system functions normally."

It's not the first time the US visa system stopped working. It also broke down in September 2003 because of a computer virus attack, the Associated Press reported at the time.

"But I think fewer international students were affected that time than now, considering the quickly growing number of people going to study in the US in recent years," said Wang, who has been in the overseas study consulting business for more than 10 years.

Su Zhou and Xinhua contributed to this story.

zhaoxinying@chinadaily.com.cn