"Syrian turns in terror suspect. I'm celebrating this. What about you, Pegida and co?" said Julia Frick on Twitter, in reference to the Islamophobic movement that has been ranting against migrants in the eastern city of Dresden.
Another Twitter user took a dig at the right-wing populist Alternative for Germany (AfD), which has been running an aggressive campaign against asylum seekers.
"Syrian turns in terror suspect tied up to police -- that's precisely the kind of citizen watch that AfD and Pegida like to drone on about," tweeted Florian Flade.
Syrer übergibt Terrorverdächtigen gefesselt an Polizei - Das ist wohl die Bürgerwehr von der AfD & Pegida so gern schwadronieren #chemnitz— Florian Flade (@FlorianFlade) October 10, 2016
Another using the handle Kraftklub quipped that "the foreigners are taking jobs away from police", turning around a common stereotype used by anti-migrant politicians.
"Detained terrorists: Pegida and company: 0, refugee: 1," said another user with the handle likedeeler.
After it emerged on Saturday that a Syrian refugee was wanted for amassing explosives in his apartment in the eastern town of Chemnitz, concerns were running high that this could place asylum seekers under a cloud of suspicion.
The arrival of 890,000 refugees last year has deeply polarised Germany, and misgivings against the newcomers run particularly deep in eastern ex-communist states like Saxony.
But the tide turned somewhat Monday when it emerged that the suspect, Jaber Albakr, was turned in to police by three of his compatriots.
The informants had overpowered the suspect and tied him up in their apartment, before calling in police, who finally took Albakr away on before dawn.
Chancellor Angela Merkel led praise for the Syrians, with her spokeswoman Ulrike Demmer pointing to "recognition for the Syrian who informed police about the suspect's whereabouts", leading to his arrest.
The deputy chief of the Federation of Police Officers, Sebastian Fiedler, also called it a "very positive sign that shows that one must not place all refugees under suspicion".
Meanwhile, others took a dig at police for not immediately pointing to the contribution of the Syrian informants in their first tweet announcing the arrest.
"Syrian turns Syrian in to police. And Saxony police is celebrating itself on Twitter," grumbled a user called ergu28.
Meanwhile, other Syrian refugees voiced relief that their fellow countrymen had caught the fugitive.
Jihad Darwish, 47, who lives near the Syrians who overpowered Albakr, stressed that "not all Syrians are like" the terror suspect.
Lauding the man who who overpowered and restrained the suspect, Darwish said: "That guy is a hero."