Westerners were getting too racy on the beaches of this Persian Gulf tourist haven, and a police crackdown on topless sunbathing, nudity and other indecent behavior has resulted in 79 arrests in recent days. Undercover officers are strolling the sand while others stand guard in new watchtowers to enforce the social mores of this Muslim city-state, which is a booming business center that is attracting growing hordes of foreign tourists. Authorities said they began the decency campaign after police detained a British man and a woman who were allegedly having sex on one of Dubai's sprawling beaches earlier this month. Over the past two weeks, police have detained a total of 79 people whose behavior was "disturbing families enjoying the beach," Zuhair Haroun, a spokesman for Dubai's Criminal Investigation Department, said Monday. First-time offenders may be issued a warning, but if caught twice, tourists could be referred to the public prosecutor for possible criminal charges, authorities said. Thousands of European and Asian expatriates live and work in Dubai, where native Emiratis make up only about 20 percent of the estimated 1.2 million residents. Shopping malls and fast food restaurants have replaced traditional Arab houses, and English has overtaken Arabic as the emirate's lingua franca. Many Emiratis and Arabs visiting from other Persian Gulf countries increasingly feel Dubai's ambition to become a cosmopolitan metropolis and tourist destination is overrunning their own traditions and contradict what they feel is culturally acceptable. Unlike elsewhere in the conservative Persian Gulf, tourists in Dubai are often seen wearing skimpy bikinis on public beaches and walk the city's streets in shorts. Alcohol is freely available in hotel bars and restaurants in this regional businesses and entertainment hub. While pursuing the police crackdown, Dubai has embarked on a public awareness campaign to remind its Western visitors and foreign residents that the city may have flashy hotels and glitzy skyscrapers but it also is a Muslim country with traditionally conservative values. The city is installing signs warning tourists in Arabic, English and several other languages not to sunbathe topless or change clothes in public, said Abdullah Mohammed Rafia, an official with the Dubai Municipality whose office is overseeing the public awareness campaign. Authorities are "taking action in response to numerous complaints" filed by people who visit the city's beaches, Rafia said. Complaints have ranged from families "offended by displays of nudity" to women sunbathers who say groups of men stare at them while at the beach. The police campaign also will target people who harass beachgoers with acts "deemed offensive, immoral or disrespectful," including loitering and voyeurism, said Dubai's acting police chief, Maj. Gen. Khamis Mattar al-Mazeina. Some tourists who were enjoying Dubai's simmering sun Monday said the new campaign left them confused about what is considered appropriate in Dubai. "I understand that I have to respect the rules of the country," said John MacLean, a British tourist on holiday with his girlfriend. But, he added, "I am not sure if I can kiss her or touch her in public."