Turkey on Tuesday detained 126 pro-Kurdish activists, journalists and lawyers in raids conducted just three weeks before a knife-edge vote that could extend President Recep Tayyip Erdogan's two-decade rule.
Police said their "counter-terror" operation was staged across 21 provinces, including Diyarbakir, the Kurdish minority's unofficial capital in Turkey.
State media said police held people suspected of financing the Kurdistan Workers' Party (PKK) or roping new members into the outlawed group.
The PKK has been proscribed as a terrorist organisation by Ankara and its Western allies for waging a decades-long armed struggle for greater autonomy in Turkey's southeast.
State media said the detained included people suspected of fomenting nearly 60 street protests since 2017.
The operation also involved suspects who allegedly transferred money to the PKK from municipalities held by the pro-Kurdish Peoples' Democratic Party (HDP).
The Diyarbakir Bar Association said the number of detentions could be as high as 150. These include 20 lawyers and three theatre actors, it said.
Reporters Without Borders said 11 journalists who worked with pro-Kurdish media were also detained.
The raids were believed to be the largest since 108 suspects were arrested in a similar operation in 2020.
'Steal the ballot box'
The arrests are likely to add pressure on the HDP ahead of the May 14 election, widely viewed as the most important in Turkey's post-Ottoman era.
Turkey's top court is winding down hearings against the HDP that could see it banned over alleged terror ties.
Prosecutors are zeroing in on alleged financial support the PKK receives from the HDP, which Erdogan casts as the militants' political wing.
The leftist party says it is being singled out for standing up to Erdogan's crackdown on civil liberties and mishandling of the economy.
The HDP called Tuesday's raids an "operation to steal the ballot box and the will of the people".
It accused Erdogan's ruling party of targeting "lawyers who will protect the ballot box and journalists who will inform the public" about government attempts to manipulate the vote.
Polls show Erdogan running neck-and-neck or losing to joint opposition candidate Kemal Kilicdaroglu.
Erdogan's control of parliament through an alliance between his Islamic-rooted party and a far-right group is also under threat.
'Kurdish mobilisation'
"They will not be able to prevent the arrival of peace, prosperity and democracy," Selahattin Demirtas, the jailed former co-leader of the HDP who ran twice against Erdogan, said on Twitter after the arrests.
The HDP will not field a presidential candidate in the election or run under its own party banner in the parliamentary portion of the vote.
It will instead field its parliamentary candidates under the lists of a new group called the Green Left Party, which supports Kilicdaroglu.
The measures are designed to shield the party in case it is banned before the vote.
The arrests "will firm Kurdish mobilisation to vote for (the Green Left Party) and boost motivation to back Kilicdaroglu," Eurasia Group director Emre Peker said on Twitter.
"But it also risks compromising the HDP-led grassroots organisation -- especially on election day."