Kansas schools already struggling to administer math and reading assessment tests have another problem now.
State education officials say unknown people launched cyber attacks against the tests.
The attackers slowed down or disabled networks used to administer the tests by overwhelming them with traffic, rather than hacking into them.
The attacks started Thursday and briefly stopped on Sunday.
Testing ran smoothly on Monday but the cyber attacks resumed on Tuesday.
Officials from the Kansas State Department of Education and the University of Kansas testing center said Tuesday no student data was compromised. The tests have already been plagued by technology problems this year; several districts have delayed or canceled administering them.