Global broadcaster Al Jazeera is combatting a large-scale cyber attack on its media platform, but all its entities remain operational.
Al Jazeera is the flagship broadcaster for Qatar, which is in a stand-off with fellow Arab states which accuse it of ties to terrorism, in a row that is endangering stability in the region.
Al Jazeera's English- and Arabic-language channels and its websites appeared to be still functioning on Thursday after the network tweeted it was "under cyber attack on all systems, websites & social media platforms".
A later tweet said Doha-based media platforms were undergoing "continual hacking attempts".
"There were attempts made on the cyber security of Al Jazeera but we are combatting them and currently all our entities are operational," a senior employee who declined to be named told Reuters.
It was the third reported hack of Qatari organisations in the last 14 months.
Qatar said last month its state news agency had been hacked and false statements attributed to the country's ruler posted, helping ignite the current rift with other Arab states.
Last April Qatar National Bank, the largest lender in the Middle East and Africa by assets, suffered a security breach and data was posted online revealing the names and passwords of a large number of customers.
Gulf dispute 'won't affect editorial independence'
Earlier, Al Jazeera said it would maintain its editorial independence despite the regional diplomatic crisis that has isolated the small Gulf Arab state.
Acting director-general Mostefa Souag dismissed accusations by some Arab powers that Al Jazeera was interfering in their affairs through its reports and defended the network's professionalism.
"All this talk about Jazeera interfering in other countries' affairs is nonsense. We don't interfere in anybody's business, we just report," he told Reuters in his office at the network's headquarters in Qatar's capital.
"If we bring (in) guests who are opposing certain governments, does that mean we are interfering in the countries' business? No. Al Jazeera's editorial policy is going to continue the same regardless of what happens with this event."
The state-funded television network is at the centre of the dispute in which Saudi Arabia, the United Arab Emirates, Egypt and Bahrain cut diplomatic ties and transport links on Monday with Qatar, which supplies natural gas to world markets.
Founded in 1996 as part of Qatar's efforts to turn its economic power into political influence, Al Jazeera won millions of viewers across the Arab world by offering uncensored debate rarely seen on other local broadcasters in the region.
Its talk shows hosted guests who challenged the wisdom of Arab rulers and adopted the role of supporter of the dispossessed. Reporters broke with a widespread taboo of the Arab news media by interviewing Israeli officials.