This post is part of our special coverage Yemen Protests 2011.

A massacre is being witnessed live, tweet by tweet, in the Yemeni capital, Sanaa. Yemeni security forces opened fire on protesters, killing at least 22 and injuring hundreds more so far. The horror is being streamed on a live feed, watched by hundreds of shocked viewers around the world.

The livefeed is brutal as many watching it reveal.

A protester who received a head wound after an attack by government security forces receives medical care at the makeshift hospital/mosque near Sana'a University. Image by Luke Somers, copyright Demotix (18/09/2011).

Virtual activism reports:

@virtualactivism: Correspondent says someone just got him the head of a man hit directly by an RPG & that he's choosing not to show it on livestream #yemen

Omar Mashjari informs us:

@OmarMash: RPJ attacks on innocent peaceful protestors targeting young men in head. There is no proportion to this evil. #Yemen #SanaaMassacre

Wounded Yemeni demonstrators are helped to a waiting ambulance during clashes following a peaceful demonstration in the capital. Sana'a. Image by Saleh Maglam, copyright Demotix (18/09/2011).

Iyad El Baghdadi confirms:

@iyad_elbaghdadi: Confirmed: Anti-aircraft guns used today by #Yemen regime loyalists against unarmed protesters. 22 killed, “hundreds” hurt. #Sanaa #Massacre

Nadine warns:

@earthtoinadine: Yemenis are some of the most armed people, yet they have still remained peaceful for months in the face of brutality. That's steadfastness.

And Mauritanian activist Nasser Weddady concludes:

@weddady: In light of the last months, today's massacres in #Yemen are a logical consequence to international apathy..

Stay tuned for more coverage from Yemen.

This post is part of our special coverage Yemen Protests 2011.