|A photo exhibit of those killed in Turkey's 1980 military coup underscores the push for constitutional reform. [AFP]
Turkish rights groups have launched petitions to try Kenan Evren, a retired general, over his role in a 1980 coup, a day after Turks voted to approve reforms that removed his immunity.
The referendum on a constitutional overhaul package on Sunday took place on the 30th anniversary of the coup led by Evren, now an ailing 93-year-old. After the military seized power, about 50 people were executed, hundreds of thousands were arrested, many were tortured, hundreds died in custody and many disappeared.
Recep Tayyip Erdogan, the prime minister, reminded Turks of the repression that followed the military takeover as he campaigned for approval of the reforms, which rewrite a charter first drawn up when the generals held sway.
Huseyin Celik, deputy chairman of the ruling AK Party (AKP), said the party's agenda was to work on a new constitution after the 2011 elections.
Turkey suffered three coups between 1960 and 1980, and in 1997 the army persuaded an Islamist-led government to resign. The military has seen itself as a guardian of secularism and the unitary state in the republic founded by Kemal Ataturk in 1923 out of the ruins of the Ottoman Empire.
Evren has defended the coup, saying military intervention was needed to bring an end to years of violence between leftist and rightist factions in which about 5,000 people were killed.
Among the 26 amendments approved by the plebiscite was a measure annulling an article blocking legal action against Evren and other leaders of the coup.
Rights groups leaped into action on Monday, filing petitions in Ankara, Istanbul and Izmir calling for Evren and at least two other coup leaders to be tried.
"This is a request that the chief prosecutor's office open a criminal case against Kenan Evren over crimes against humanity," the Human Rights Association said in a petition filed with the Ankara chief prosecutor's office.
Some legal experts have argued that a statute of limitations would prevent the coup leaders being put on trial. Evren became Turkey's president in the wake of the coup, a position he held until 1989.
He came to Ankara to vote in Sunday's referendum.
It is common currency among Turks that the US Central Intelligence Agency played a part in destabilising Turkey in the late 1970s to pave the way for a military takeover in its frontline Cold War ally.
About 58 per cent of Turks voted in favour of constitutional changes proposed by the government. The referendum results boosted markets and the AKP's prospects of winning a third term in power.
Opponents had argued that some of the changes would result in the AKP gaining influence over the judiciary.