DUBAI, United Arab Emirates (AP) — Iran’s security forces deployed in large numbers across the capital on Sunday, expecting more protests after its Revolutionary Guard admitted to accidentally shooting down a passenger plane at a time of soaring tensions with the United States. Riot police in black uniforms and helmets massed in Vali-e Asr Square, Tehran University and other landmarks as calls circulated for protests later in the day. Revolutionary Guard members patrolled the city on motorbikes and plainclothes security men were also out in force. People looked down as they walked briskly past the police, hoping not to draw attention to themselves. The plane crash early Wednesday killed all 176 people on board, mostly Iranians and Iranian-Canadians. After initially pointing to a technical failure and insisting the armed forces were not to blame, authorities on Saturday finally admitted to accidentally shooting it down in the face of mounting evidence and accusations by Western leaders.