Satellite news network Al Jazeera says it has come under a large scale cyber-attack.
Al Jazeera is the flagship broadcaster for Qatar, which is in a stand-off with neighbouring Arab states over alleged ties to terrorism, a row which is endangering stability in the region.
"Al Jazeera Media Network under cyber-attack on all systems, websites & social media platforms," it said on Twitter on Thursday. Reuters could not immediately validate the report.
The dispute between Qatar and some Arab states is threatening the stability of the entire region, Qatar's foreign minister says.
Sheikh Mohammed bin Abdulrahman al-Thani added that diplomacy is still Doha's preferred option and there would never be a military solution to the problem.
He told reporters on Thursday that Qatar had never experienced this type of hostility, even from an enemy country.
He said there had been no change to Qatar's military deployment and no troops had been moved.
He was speaking after Saudi Arabia, the United Arab Emirates and several other countries severed diplomatic ties with Doha on Monday and closed transport links.