Below is a breakdown of unrest since disputed 2002 elections in Zimbabwe, as the southern African country votes on Saturday in a referendum on a new constitution which is supposed to lead to fairer elections:
- March 9-11, 2002: President Robert Mugabe is re-elected president in a poll marred by violence and widely denounced as rigged. Western sanctions are imposed.
- June 6, 2003: The head of the main opposition party, the Movement for Democratic Change, Morgan Tsvangirai, is arrested for the second time in five days and again charged with "treason". He is freed on bail on the 20.
- October 15, 2004: Tsvangirai is cleared of charges of plotting to kill Mugabe.
- May 22, 2005: The authorities launch "Operation Murambatsvina", or "drive out the trash," which the UN says leaves an estimated 700,000 people homeless.
- August 2: Tsvangirai is cleared of treason charges carrying a possible death sentence.
- March 11, 2007: Tsvangirai is arrested and two activists killed after riot police thwart a planned mass protest against Mugabe's government.
- March 18: MDC spokesman Nelson Chamisa is attacked and seriously injured by suspected state security agents.
- March 27-28: Tsvangirai and around 30 MDC members of staff are detained in a raid at the opposition party's headquarters.
- March 29, 2008: Tsvangirai leads Mugabe in the first round of the presidential election, but drops out ahead of the run-off, citing violence against his supporters. The United Nations blames supporters of the regime for violence in which more than 180 are killed and 9,000 injured, according to Amnesty International.
- February 11, 2009: Tsvangirai is sworn in as prime minister under a power-sharing deal. On the 13, the new unity government is sworn in at a historic ceremony tarnished by the arrest of an MDC official, the white former deputy Roy Bennett, who was set to become deputy agriculture minister.
- January 27, 2012: Amnesty International calls on Zimbabwean authorities to refrain from manipulating the country's laws to harass human rights activists and opponents of Mugabe.
- November 26: Rights groups voice fears that the Zimbabwean authorities will launch a crackdown on rights activists ahead of the referendum and elections scheduled for 2013.
- March 15, 2013: Seven members of the MDC are assaulted by supporters of Mugabe, heightening tensions on the eve of the referendum.