Widespread technical glitches interrupted thousands of Fairfax County schools students taking Virginia’s standards of learning tests online Thursday.

In a letter to parents, the district acknowledged “significant problems” while administering the online tests due to an outage with the school system’s Internet service provider.

About half of Fairfax County schools were affected by the Internet outage, the administration said. Many schools had to cancel the testing and students will finish the exams at a later date.

It was not immediately clear how many total students taking the tests were affected. A total of 41,975 tests were scheduled on Thursday. Of those, at least 3,281 students will take the tests at a later date. About 4,126 students were delayed by Thursday’s outage, but were able to finish the exam on teh same day.

The administration said the Internet problems have been fixed and testing will resume Friday. All schools were required to give the state exams between May 13 and June 7.

For the first time, Virginia students this year logged on to a Web site to take the exams as opposed to traditionally completing the paper tests by filling in multiple choice “bubbles” using No. 2 pencils.

But the online exams have encountered technical problems in other states recently. Earlier this year, computer issues and internet disruptions plagued students in Kentucky, Indiana, Minnesota and Oklahoma.