The forbidden politicians are Leyla Zana, Gültan Kisanak, Sebahat Tuncel, Salih Yildiz, Ertugrul Kürkçü, Hatip Dicle, Çiçek Otlu, Nezir Sincar, Serafettin Efe, Harun Özcan, Abdullah Kizilay, Isa Gürbüz.

Dozens of Kurdish politicians who support the pro-Kurdish Peace and Democracy Party (BDP) had announced that they would run as independent candidates in national elections set for June 12 in an attempt to get over the 10 percent threshold in Turkey for parties to enter parliament.

BDP said after the bans it was pondering whether to withdraw from June elections.

Selahattin Demirtas, chairman of the BDP, called the election board’s decision ‘a political operation’ that would benefit the ruling Justice and Development Party (AKP) in the elections.

Demirtas said half of 12 independent candidate blocked by the Supreme Election Board due to past convictions were candidates supported by his party. They included two Kurdish lawmakers and Leyla Zana, a Kurdish rights activist and former legislator who spent a decade in prison after being convicted of links to outlawed Kurdish Workers’ Party, or PKK.

Ahmet Türk, a senior party official, said, "the participation of the Kurds in democractic politics was being blocked."

Thousands of people marched to the ruling AKP office in Diyarbakir. Some clashes have been reported there as people chanted slogans against PM Erdogan seen as one of the plotter against Kurdish politicians.

Demonstrations have also been staged in Batman, Mersin and Van. Twitter and social networks were used to spread the word around and call on people to join a protest in Istanbul central Taksim square.