Nearly 100 people were killed and at least 200 injured when a suicide blast ^[1] targeted a military parade rehearsal in Yemen's capital Sana'a on May 21.

The bomber, dressed in military uniform, detonated his explosives in the middle of soldiers rehearsing for a parade to mark the 22nd anniversary of the unification ^[2] of North and South Yemen.

Al Qaeda (AQAP ^[3]) have apparently claimed responsibility ^[4] for the attack, in revenge for what it described as the US war ^[5] against it in southern Yemen. However, many Yemenis have expressed their doubts.

The following video ^[6] [ar] shows the immediate aftermath of the explosion on Sabaeen Street in Sana'a [WARNING: DISTRESSING IMAGES].

Journalist Tom Finn was at the scene:

@tomfinn2 ^[7]: In Sabaeen. Police everywhere, pieces of flesh scattered over the tarmac. Injured all in hospital. ‪#yemen‬

@tomfinn2 ^[8]: Ambulances still racing around Sana'a. Doctors say hospitals are overwhelmed. ‪#Yemen‬

Yemen Updates tweeted a very graphic photo ^[9] of some of the soldiers killed in the suicide bombing, and Ibrahim Mothana tweeted a link ^[10] to a graphic video ^[11].

Farea Al Muslimi, a student activist based in Beirut, commented:

@almuslimi ^[12]: This is a terrifying day in ‪#Yemen‬ and at the same time golden chance for [President Abdou Rabbo Mansour] ‪#Hadi‬ to take urgent strong measures in restructuring the army.

President Hadi indeed issued a decree ^[13] [ar] after the attack replacing top security officials, including a nephew of former president Ali Adullah Saleh.

Mai Saleh tweeted:

@A4Mai ^[14]: Fadhel AlQawsi is appointed as the new commander of the Central Security forces by decree of President ‪#Hadi‬ ‪#Yemen

She added:

@A4Mai ^[15]: So Ammar [Saleh's nephew] is out? Did we have to witness a disaster for these decrees to come? ‪#Yemen‬

^[16]

The site of the suicide bomb attack in Sana'a, Yemen that claimed the lives of at least 96 soldiers. Photo by Luke Somers, copyright © Demotix (21/5/2012).

Although some news sources have stated that Al Qaeda has claimed responsibility for the attack, many are waiting to learn more.

Yemen scholar Gregory D. Johnsen commented:

@gregorydjohnsen: ^[17] Less rumor mongering please about today's attack in ‪#Yemen‬. I promise it is ok to say: “I don't know”

And demanding more evidence, Mai Saleh tweeted:

@A4Mai: ^[18] Would love to see that ‪#AQAP‬ statement in which it claimed responsibility for the attack ‪#Yemen‬

News of Yemen Revolution ^[19] Facebook page posted that 12 hours prior to the explosion, a pro-Saleh page on FB predicted the explosion and provided a link, which was subsequently removed.

Mohammed wondered how the suicide bomber went unnoticed:

@Yemen4Change ^[20]: ‪#Yemen‬ | the word is: the suicide bomber was wearing military clothes & a belt packed with explosives, NO ONE NOTICED? ‪#Sanaa

‬While Farea Al Muslimi asked:

@almuslimi ^[21]: Why didn't ‪#Saudi‬ help by intelligence info about ‪#AQAP‬ as it did regarding the bombs being sent to ‪#US‬? ‪#Justwondering‬ ‪#YEMEN‬

Amid the many speculations and question marks, Yemen's Human Rights Minister Hooria Mashhour tweeted:

@Hooria_Mashhour ^[22]: Transparent investigation should be done for all these mass crimes against humanity ‪#yemen‬

Ataf Alwazir, a prominent Yemeni activist and blogger, encouraged people to look deeper than the repetitive news circulating:

@WomanfromYemen ^[23]: always keep an open mind & dont take everything as it is. Dont be a copy paste person. Question & analyze. Thats why we have a mind.

The day of the blast was certainly one of the saddest days Sana'a and Yemen have ever seen. The attack raises questions regarding the efficacy of the joint US-Yemeni counterterrorism strategy, and give credence to the argument ^[24] that US drone strikes are counterproductive and simply fuel extremism.