Supporters of ousted Burmese leader Aung San Suu Kyi clashed with police on Friday as hundreds of thousands joined nationwide pro-democracy demonstrations in defiance of the military junta’s call to halt mass gatherings. The United Nations human rights office said more than 350 people, including officials, activists and monks, have been arrested in Burma since the Feb. 1 coup, including some who face criminal charges on “dubious grounds.” The U.N. rights investigator for Burma, which is also known as Myanmar, told a special session of the Human Rights Council in Geneva that there were “growing reports, photographic evidence” that security forces have used live ammunition against protesters, in violation of international law. Special Rapporteur Thomas Andrews urged the U.N. Security Council to consider imposing sanctions and arms embargoes. Myint Thu, Burma’s ambassador to the United Nations in Geneva, told the session that Burma did not want “to stall the nascent democratic …