The campaign posters are inflammatory: Minarets rising like missiles from the national flag.
A proposal championed by right-wing parties to ban minarets in Switzerland goes to a nationwide vote on Sunday in a referendum that has set off an emotional debate about national identity and stirred fears of boycotts and violent reactions from Muslim countries.
With tensions running high, the Geneva Mosque was vandalized Thursday by unidentified individuals who threw a pot of pink paint at the building's entrance.
It was the third incident against the mosque this month: earlier, a vehicle with a loudspeaker drove through the area imitating a muezzin's call to prayer, and vandals threw cobble stones at the building, damaging a mosaic.
Business leaders say a minaret ban would be disastrous for the Swiss economy because it could drive away wealthy Muslims who bank in Switzerland, buy the country's luxury goods, and frequent its resorts.
The vote taps into anxieties about Muslims that have been rippling through Europe in recent years, ranging from French fears of women in body veils to Dutch alarm over the murder by a Muslim fanatic of a filmmaker who made a documentary that criticized Islam.
Polls indicate growing support for the proposal submitted by the anti-immigrant Swiss People's Party, but it was doubtful it will gain enough momentum to pass. Muslims in Switzerland have kept a low profile, refraining from a counter-campaign.
"Switzerland's good reputation as an open, tolerant and secure country may be lost and this would bring a blow to tourism," said Swiss Hotel Association spokesman Thomas Allemann.
The nationalist Swiss People's Party has led several campaigns against foreigners, including a proposal to kick out entire families of foreigners if one of their children breaks a law and a bid to subject citizenship applications to a popular vote.
The party's controversial posters have shown three white sheep kicking out a black sheep and a swarm of brown hands grabbing Swiss passports from a box.
The current campaign posters showing missile-like minarets atop the national flag and a fully veiled woman have drawn anger of local officials and rights defenders.
The cities of Basel, Lausanne and Fribourg banned the billboards, saying they painted a "racist, disrespectful and dangerous image" of Islam.
The U.N. Human Rights Committee called the posters discriminatory and said Switzerland would violate international law if it bans minarets.
The Swiss People's Party joined forces with the fringe Federal Democratic Union in the campaign. They say they are acting to fight the spread of political Islam, arguing the minaret represents a bid for power and is not just a religious symbol.
The four minarets already attached to mosques in the country would remain even if the referendum passes. Minarets are typically built next to mosques for religious leaders to call the faithful to prayer, but they are not used for that in Switzerland.
Construction of traditional mosques and minarets in European countries has rarely been trouble-free: projects in Sweden, France, Italy, Austria, Greece, Germany and Slovenia have met protests but have rarely been blocked.
In Cologne, Germany, plans to expand the city's Ditib Mosque and complete it with a dome and two 177-foot-tall minarets have triggered an outcry from right-wing groups and the city's Roman Catholic archbishop.
People's Party lawmaker Walter Wobmann said minarets are part of Muslims' strategy to make Switzerland Islamic. He said he feared Shariah law, which would create "parallel societies" where honor killings, forced marriages and even stoning are practiced.
Organizers collected more than the 100,000 signatures required for any Swiss citizen to put a constitutional initiative to a nationwide vote.
The government has urged voters to reject the initiative, saying it would violate religious freedom. Foreign Minister Micheline Calmy-Rey has warned it would lead to a security risk for Switzerland; other members of the multiparty government have spoken out against the proposal.
Between 350,000 and 400,000 of Switzerland's 7.5 million people are Muslims. Many are from families who came to Switzerland as refugees from former Yugoslavia during the 1990s.
Less than 13 percent of the Muslims living in the Alpine nation are practicing and most are well integrated, said Justice Minister Eveline Widmer-Schlumpf. She said initiative would "endanger religious peace in our country."
A survey by the respected polling institute gfs.bern last week indicated that 53 percent of voters reject the initiative, although support has grown by 3 percentage points to 37 percent since last month. Typically in Switzerland the margins on such votes narrows as balloting nears. Ten percent of the 1,213 people polled were undecided. The survey had an error margin of 2.9 percent.
"The problem is not so much the minarets, but rather what they represent," said Madeleine Trincat, a retiree from Geneva. "After the minarets, the muezzins will come, then they'll ask us to wear veils and so on."
Carlo Adler, the director of a luxury jewelry shop in Geneva, called the initiative xenophobic.
"I don't see why they should be banned," he said about minarets. "We might as well take off the spires from churches."
The Swiss business organization economiesuisse said it fears a minaret ban would harm Switzerland's image in the Islamic world. The exporting nation sold goods of around 14.5 billion Swiss francs (about $14 billion) to Muslim countries last year, according to economiesuisse.
Peter Spuhler, the head of Swiss Stadler Rail Group, a train and tramway exporting company with markets in Muslim countries, said, "reactions can be very emotional and fierce" if the initiative is accepted.
"This can lead to boycotts," he told weekly SonntagsZeitung.