Just days after Saudi Arabia began airstrikes  on Yemen in a regional effort to wrest control from Houthi rebels, Yemen's largest Internet service provider, Yemen Net, appears to have blocked several major news and media websites.
Houthis took control of state media in January, an act strongly condemned by the United Nations , this is one of the first documented instances of broad-based online censorship since the rebel group ousted the nation's president  and cabinet in January.
The local chapter of the Internet Society (ISOC) for Yemen posted calls on both their Facebook  and Twitter accounts asking followers to identify all websites that were inaccessible. Thus far, news sites including Mareb Press , Yemen Voice , Sahafa Net , Al-Sahwa Net  and Yemen Press  appear to have been blocked.
— جمعية الإنترنت-اليمن (@ISOC_Yemen) March 26, 2015 
Has your website or a website that you usually visit in Yemen been blocked? Please let us know by commenting on this post or via email on email@example.com
— Fahmi Albaheth فهمي (@albaheth4) March 26, 2015 
Fahmi also tweeted a resource on how to circumvent the block:
— Fahmi Albaheth فهمي (@albaheth4) March 27, 2015 
ISOC-Yemen posted a statement  on their Facebook page regarding the acts of web censorship:
Statement by ISOC-Yemen on Recent Acts of Web Censorship
As an independent organization concerned with the right of users to access the Internet freely, the Internet Society Yemen Chapter (ISOC-Yemen) condemns and denounces the acts of censorship that have recently targeted several Yemeni websites. ISOC-Yemen urgently calls upon the Yemeni authorities involved to immediately unblock those websites and stresses that the current turmoil in Yemen should not be used as a pretext to tamper with accessing the Internet, which should remain open for all users to use without restrictions.
Issued in Sana'a on Friday, March 27, 2015
Internet Society Yemen Chapter (ISOC-Yemen)
The Association for Progressive Communications (APC) condemned the act of censorship:
— APC (@APC_News) March 27, 2015 
We reached out to Walid Al-Saqaf, president  of ISOC-Yemen and the founder of Yemen Portal  for more information. Al-Saqaf noted that the kind of blocking that authorities had used appeared suspiciously similar to what users faced  some years ago, between 2005 and 2011. He explained that the only difference is that now the banning includes websites critical of Houthis, in addition to websites critical of former president Ali Abdullah Saleh. In the past, Saleh had blocked Houthi websites, yet now Houthis are blocking websites that criticize their alliance (which Al-Saqaf described as “unholy”) with Saleh.
He also added that since the Houthi forces took over the capital and occupied all government offices, they were able to control all vital communication establishments such as the Public Telecommunications Corporation which controls Yemen's main ISP and mobile operator, along with the Ministries of Communication and Information, which control landlines and state media. Thus, Houthis can now send directives to any official asking them to take actions against a media outlet. Al-Saqaf believes that this explains what he says is an extreme pro-Houthi bias in state media and the blocking of websites that include any critique of Houthi politics.
Regarding the official warning issued by the Ministry of Information, Al-Saqaf described the allegation as “inciting tension” as an easy pretense for limiting media freedom. He added that this was the same pretext under which the Aljazeera office was raided  and equipment confiscated in 2011.
Thus far, there have been no official statements issued by Yemen Net or the Ministries of Communication and Information regarding these acts of censorship.