Senegalese opposition leader Ousmane Sonko said that he survived an assassination attempt during his recent trial that sparked a deadly protest last week.   Sonko, a fierce opponent of President Macky Sall, has been receiving medical treatment since he was allegedly sprayed with an unknown "toxic product" and assaulted while authorities escorted him to a courthouse on March 16. "We sent samples of the product abroad that was on our clothes. We wanted to identify the product" he said, in a video posted on his Facebook page.