Armenia's government and the country's opposition are taking part in events to mark the massacre of 1.5 million Armenians a century ago by Ottoman Turks.

Tuesday's commemoration of the massacre that began 103 years ago —viewed by Armenians and many historians as genocide — comes after the country's prime minister resigned in a surprise move following days of anti-government protests.

Armenia's acting prime minister and other officials laid flowers at a hilltop memorial complex in Armenia's capital Tuesday morning along with thousands of residents. Leaders of the opposition and their supporters were marching to the memorial later on Tuesday.

Turkey, the successor to the Ottoman Empire, vehemently denies that the massacre was genocide and insists it was part of the violence during World War I.