The Twitter account of Al Jazeera network's Arabic language channel was restored after a temporary suspension on Saturday.
The @ajarabic account resumed, with a message saying: "We bring the attention of our followers to the fact that our main al jazeera account @ajarabic is now working again."
"The account of al Jazeera on twitter @ajarabic is currently suspended due to what seems to be an organised campaign and we are doing the necessary work to get the service back," Al Jazeera said on another of its Twitter accounts for its breaking news service after the Twitter account was blocked earlier during the day.
No comment was immediately available from Twitter.
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.
The network said on June 8 it was combating a large-scale cyber attack but that all its entities remained in operation.
Saudi Arabia, Egypt, the United Arab Emirates and Bahrain have broken off ties and imposed sanctions on Qatar, accusing it of supporting terrorism and courting regional rival Iran - allegations Doha denies.
Twitter was a key means of communication for protesters during the Arab uprisings in 2011, violence that threatened Saudi Arabia until the kingdom unveiled a populist $130 billion social spending package. Al Jazeera's coverage of the uprisings in the region had also won it millions of viewers in the Middle East.
Saudi Arabian billionaire Prince Alwaleed bin Talal and his investment firm Kingdom Holding together own more than 5 percent of Twitter Inc.