Three pro-Kurdish mayors replaced in southeastern Turkey

Three elected Kurdish mayors were replaced in the country's southeast following sweeping detentions of more than 400 people over alleged links to the Kurdistan Workers Party (PKK).

According to the interior ministry, mayors in Diyarbakir, Mardin and Van - major cities in the mainly Kurdish southeast - were accused of various crimes including membership of a terrorist organisation and spreading terrorist group propaganda.

The dismissed mayors, elected candidates of the left-wing pro-Kurdish People's Democracy Party (HDP), were all replaced with state-appointed officials.

"For the health of the investigations, they have been temporarily removed from their posts as a precaution," said the ministry, referring to Diyarbakir Mayor Selcuk Mizrakli, Mardin Mayor Ahmet Turk and Van Mayor Bedia Ozgokce Ertan.

Ahead of nationwide local elections in March, President Recep Tayyip Erdogan had warned of such a move against elected officials if they were found to have connections to the PKK, which has been in a war with the Turkish state since 1984.

CNN Turk showed police sealing off the municipality headquarters in Diyarbakir with metal barriers, with water cannon vehicles and riot police deployed outside.

HDP MP Garo Paylan criticised the move on Twitter.

"All political parties and society should react to this vile coup against the will of the people," he wrote.

On Twitter, former prime minister Ahmet Davutoglu also criticised the move as a "a violation of the spirit of the democratic system" while Mayor of Istanbul Ekrem Imamoglu warned that "ignoring the will of the people" was "unacceptable".

The Interior Ministry also said on Twitter that police detained 418 people in 29 provinces in an investigation targeting suspects with links to the PKK.

Riot police fired water cannon on small groups of people protesting against the mayors' dismissal in central Diyarbakir, where police sealed off the municipality headquarters with metal barriers, Reuters TV video showed.

The removal of the mayors echoed the dismissal of dozens of mayors in 2016 over similar accusations, part of a purge that began after a failed coup.

Nearly 100 mayors and thousands of party members were jailed in a crackdown that drew expressions of concern from the United States and European Union.

Ahead of the March election Interior Minister Suleyman Soylu said 178 current election candidates were being investigated over alleged PKK links.

Erdogan at the time warned that HDP mayors could again be dismissed if they, like their predecessors, are deemed to have ties to militants.

Erdogan frequently accuses the HDP of links to the PKK, which is designated a terrorist group by Turkey, the European Union and the United States. The HDP denies such links.

More than 40,000 people have been killed in the decades-long conflict with the PKK.