CARACAS: Riot cops fired tear gas to head off a protest march Wednesday by opponents of Venezuela’s President Nicolas Maduro, who were demanding a referendum on removing him from office. Political leaders and analysts warned tensions could erupt into unrest as the center-right opposition staged rallies across the crisis-hit South American country. Protesters were demanding electoral authorities quickly approve their call for a vote on dumping the socialist leader. Security forces blocked the street to keep demonstrators away from the headquarters of the National Electoral Board (CNE) in Caracas. A small number of tear gas canisters were fired. The opposition coalition MUD said in a statement that one of its top leaders, Henrique Capriles, was affected by the tear gas as he led the march. The Democratic Unity Roundtable (MUD) blames Maduro for an economic crisis in which Venezuelans are having to queue for hours for rations of basic food and other goods. Maduro has also imposed daily electricity blackouts and has public employees working just two days a week due to power shortages.