Turkish officials detained more than 100 participants in an anti-NATO march arranged by the Communist Party of Turkey on Sunday, just before an alliance leaders meeting scheduled for Ankara this week, the party announced in a release.

Turkey is set to welcome heads of state from all 32 member nations plus partner representatives in the capital for talks on Tuesday and Wednesday. Security has been tightened throughout Ankara, with public gatherings prohibited, major zones blocked off, and numerous streets sealed.

The TKP stated it had planned the march in central Kizilay Square, noting that more than 100 members, among them several leaders, were taken into custody.

Recorded scenes displayed flag-carrying demonstrators chanting slogans such as 'Murderer NATO, leave the nation' and 'No entry for NATO,' leading riot police to fire tear gas and disperse the groups.

Separately, the TKP held another rally in Istanbul where hundreds marched from Taksim Square toward Dolmabahce. Two additional demonstrations by leftist organizations took place in the Kadikoy area. Although police maintained a strong presence, the Istanbul events remained peaceful without clashes.

'We assembled today across many regions of Turkey to voice opposition to NATO,' TKP Secretary General Kemal Okuyan stated in Istanbul.

'We pledged not to surrender Ankara to NATO backers and not to let the capital stay quiet. We kept that pledge.'

The government offered no immediate response regarding the rallies or the detentions.

Nearly 40 Journalists and Academics Held in Turkish Anti-Terror Operations

Officials last month took 103 individuals into custody during anti-terror sweeps in Ankara that initially detained 225 people.

In a separate action, 39 others, among them reporters from independent media, activists, and scholars, were detained in anti-terror operations nationwide, according to reports on Sunday.

Tuncer Bakirhan, co-chair of the pro-Kurdish DEM Party, and main opposition Republican People's Party court-appointed leader Kemal Kilicdaroglu condemned the detentions as unacceptable restrictions on fundamental freedoms ahead of the NATO summit.

'The country has been turned into one large detention facility by using the NATO summit as justification,' Bakirhan posted on X. 'We are experiencing days of undeclared martial law.'

Turkish prosecutors have described the operations as efforts to address militant group activities, without reference to the summit.