A police spokesperson told AFP that the graffiti, found on Sunday morning, were being "investigated by the national security agency".
It is the latest in a series of anti-Islamic - and anti-Semitic - acts of vandalism in EU member state Austria.
PEGIDA, which has drawn thousands of supporters on the streets of the German city of Dresden is recent months, was due to hold its first march in Austria on Monday evening.
Small "Patriotic Europeans Against the Islamisation of the Occident" offshoots have also sprung up in other German cities and in European countries including Denmark, Switzerland and Spain.
The Vienna march in the city centre was expected to attract fewer than 300 people. A counter-demo was also planned, with 1,200 extra police on duty in case of trouble.
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In December, unknown culprits left a pig's head and intestines in front of the door of another mosque in the capital. A street sign was changed to read "Sharia Street" in September.
This weekend four swastikas and the word "Hitler" were found drawn and etched on walls on the former Nazi concentration camp Mauthausen.
On Saturday night two men were assaulted in central Vienna by four others shouting anti-Semitic slogans such as "Scheissjuden" ("shitty Jews"), media reports said.
Meanwhile, the number of anti-Muslim incidents in France has soared since the Paris attacks, with 128 such acts registered over two weeks, almost the same amount as all 2014, according the French National Observatory Against Islamophobia.
Intolerance, extremism on the rise
A senior European Union official warned on Monday about rising levels of extremism and intolerance across the 28-nation bloc, targeting Jews, Muslims, homosexuals and even women.
"There is rising anti-Semitism, there is rising Islamophobia, there is rising homophobia," Frans Timmermans, deputy to European Commission President Jean-Claude told parliamentarians from EU states meeting in Latvia's capital Riga.
"There are people who are actually challenging the position of women in European society," said Timmermans, who was visiting the Baltic state in connection with the six-month rotating EU presidency which Latvia has assumed.
"This cannot happen. We need to put the rule of law front and centre in our European discussions because if we don't have that, we have nothing.
"If Jews in this Europe cannot feel at home, Europe is finished. If Jews believe their future is not in Europe, Europe has no future. And this applies to Muslims alike - and to other minorities. If gay people think they have to go back into the closet, we have no future for Europe," he added.
COMMENTS (9)
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@ Naren, you asked why muslims.......Well where do I start!!!!!!!
@ajeet: Lucky U usually ET does not pub any comment against Muslims or Pakistan .
@Pity: Why it is against Muslims only. Any clue!
Why fear at your own game. Game of hate, violence.
Muslims should understand that You change ur self otherwise world will change you forever. You can't get away by saying We condemn extremists. But u will have to bring change within u. World is awaking now. Don't compare things with waht happened in 19 n 20th century but we are in 21st century now. So plz stop being 7th century's human. Be moderate, be logical, n finally above all live n let others live. Thanks
Muslims started this fire.
So called civilized people are becoming uncivilized and intolerant. The thing they complain about Muslims, they are adapting themselves. Ironic but I'm sure some people will justify it one way or another.
Muslims are labelled as extremists but the demos being staged by PEGIDA portray the extremist side of the European countries.
To my Muslim brethren in Germany and Austria - stay safe . May the gods above be with u wherever u go .