“Perhaps this explosion would not have happened if we had not brought unknown people into the country,” a Twitter user calling himself Mehmet Guzel wrote hours after the attack. "Syrians should be expelled from this country immediately."
Another user posted the hashtag #suriyeli with a video of people fleeing the scene of the November 13 attack, which killed at least eight people.
This and thousands more posts contained anti-Syrian sentiment — even after the Turkish government blamed armed Kurdish groups for the attack.
Both the Kurdistan Workers' Party (PKK) and the US-backed Syrian Democratic Forces, a mainly Kurdish militia in Syria, denied involvement and called for an investigation into the circumstances surrounding the attack.
The chief suspect, Ankara said, was trained in Syrian towns near the border with Turkey. President Recep Tayyip Erdogan has since launched an offensive into northern Syria targeting the groups.
Orwa Ajjoub, a senior analyst at Coar Global, said such incidents did little to defuse the tension felt by the almost four million Syrian refugees living in Turkey, especially with presidential and parliamentary elections coming next year.
“These events will all feed into the anti-Syrian sentiments pre-election,” he said. "It's going to definitely be used by the opposition and the AKP [ruling party] as well to justify military operations into Syria."
Days after the incident, Mr Erdogan’s chief adviser acknowledged that racism and xenophobic rhetoric against Syrians exists even among government ranks.
“The opposition in Turkey uses a racist line and provokes people by saying that [Syrians] are taking their jobs and are a menace to Turkey,” Ilnur Cevik told The National.
“Some people inside and close to the administration also get carried away with this kind of propaganda because it’s very tempting and attractive.”
Statements by public officials have also had an effect on the ground.
A Syrian activist, who declined to be named for security reasons, said he had faced difficulty when trying to rent a house in Istanbul.
“Racism is very prevalent in Turkey,” he told The National. "Every time I called someone to inquire about an advertised home, I’d get asked where I’m from. When I say I’m Syrian, the owner refuses my business."
Mr Cevik said officials have been “politicising” the issue of refugees in Turkey, months before June’s presidential and parliamentary elections.
In September, head of Turkey's far-right Victory party, Umit Ozdag, made unverified claims that the Turkish government gave “over-the-phone” citizenship to 1.5 million Syrians — five times the official figure.
In another statement, he said Turkey had been “invaded” by Syrians and he promised to “send all refugees back” if his party wins at the polls.
"We want them to go back home,” Mr Cevik said, referring to the Syrian refugee population as Turkey’s “guests”.
“If they were there for a year, that’s no problem, but they’ve overextended their stay by a decade or more. That creates internal problems.”
He conceded that it would be “against international law” to forcibly deport refugees back to Syria. Last month, Human Rights Watch said Turkey had “arbitrarily arrested, detained and deported hundreds” of Syrian refugees between February and July.
Mr Cevik said Turkish security forces had tried to “contain” the refugee population by enforcing laws that ensure Syrians make up no more than 25 per cent of the demographic in Turkish districts.
"Some of the laws issued in the past weeks, and the dire economic situation, have caused the refugees to actually flee the country — even those who are freshly in from Syria are trying to go to Greece via Turkey because it's safe," said Suhail Al Ghazi, who lived in Turkey for six years before deciding to leave for better work opportunities.
When the war broke out in Syria 11 years ago, Turkey stood firmly against the Syrian government and President Bashar Al Assad.
A few weeks after the Sochi encounter, Mr Erdogan alluded to the possibility of restoring ties with Syria, saying: "Political dialogue or diplomacy cannot be cut off between states."
Turkish officials have also said they had been exchanging intelligence and meeting their Syrian counterparts.
Mr Cevik called this a logistical “practicality”.
“It’s a necessary security co-operation, a necessary practicality because they’re our neighbours whether we like it or not.”
Turkey’s public admission of continuing dealings with the Assad regime caused outrage among the Syrian opposition.
"Those who thought that Turkey was standing with them for their opposition of the Syrian government were wrong," Mr Ajjoub said. "It upset the Syrian opposition when Mr Erdogan made his latest comments on rapprochement.
"It was like a bomb dropped."