Authorities on Tuesday detained eight members of the Turkish Medical Association's (TTB) central council who had denounced Ankara's military operation against a Syrian Kurdish militia, state media reported.
Eleven arrest warrants were issued for council members, eight of whom were detained, including the association's head, Rasit Tukel.
Prosecutors began an investigation into the TTB council on Monday after it issued a statement last week which said "war is a man-made public health problem".
The TTB also said that conflicts lead to "irreparable problems".
The comments led to angry remarks on Friday from President Recep Tayyip Erdogan about the "so-called Turkish Medical Association" whose members he described as "terrorist-lovers".
The association's head office received a "large number of threats of violence by email and phone calls", human rights group Amnesty International said.
Mr Erdogan again hit out at the group on Sunday: "They are not intellectuals, they are a gang of unthinking slaves... They are the servants of imperialism."
The TTB ended its statement on Wednesday by saying "No to war".
The Turkish leader described their stance as "real filth", adding: "Actually this is the dishonourable stance that should be said 'No' to."
Turkey launched a cross-border offensive supporting Syrian rebels with ground troops and air strikes on January 20 against the Kurdish People's Protection Units (YPG) militia in its western Syrian enclave of Afrin.
Ankara refers to the YPG as a "terrorist" offshoot of the outlawed Kurdistan Workers' Party (PKK), waging an insurgency against the Turkish state since 1984.
The PKK is blacklisted as a terrorist group by Ankara and its Western allies.
"As the authorities go after those accused of deliberate disinformation", Mr Erdogan's spokesman Ibrahim Kalin warned the public and media to be wary of "lying, fake, distortive and provocative news, images and gossip".
The interior ministry on Monday said 311 people including journalists and activists had been detained over accusations they were spreading "terror propaganda". The suspects have been taken into custody.