There is growing international concern about attacks on demonstrators by Yemeni security forces and their allies. On Saturday, several people died (the exact number is unclear) during a pre-dawn offensive against the protesters' camp at Sana'a University. 

Across the country, more than 30 protesters have been killed in recent weeks, according to various reports.

The UN secretary-general, Ban Ki-moon, issued a statementyesterday condemning the excessive use of force and Human Rights Watch has called for a suspension of military and security assistance to Yemen. 

The British foreign secretary, William Hague, also described the violence as "unacceptable" – though unfortunately one of Britain's biggest arms companies has a role in it.

The Yemeni website al-Masdar Online claims that munitions used in the Sana'a attack, including smoke bombs and CS gas, were from a five-ton consignment provided by the United States in the second half of last year to assist the Yemeni government in combating terrorism.

The website has several pictures showing collections of used munitions. The markings on them are not very clear in the photographs but one is a Number 19 CS gas canister with a manufacturer's address in Casper, Wyoming. 

Casper is the home of Defense Technology (owned by the British company, BAE Systems) which is a major supplier of CS gas.

Jeb Boone has an interesting blog post from the scene of yesterday's violence in Sana'a. "Yemeni military and security forces are spread so thin that they are now being sent to complete impossible tasks," he writes. The fact that they were heavily outnumbered by demonstrators may explain why they acted so violently – before retreating. Boone continues:

"I won’t be surprised to see soldiers begining to join the protests. I’m fairly sure that the only reason many haven’t already done so is because they don’t want to lose their job. As it becomes clearer that Saleh’s days are numbered and soldiers continue to be sent off to fulfil impossible and incredibly dangerous tasks, they’re going to start defecting."

Posted by Brian Whitaker, 13 March 2011