Istanbul remains one of the most visited cities in the world, attracting millions of tourists every year.However, it has recently been listed as a potential target for violence, as Turkey has become embroiled in conflict with the Islamic State of Iraq and al-Sham (ISIS) and the PKK.Some countries, including the U.K., Germany and Scandinavian countries, have issued official warnings to their citizens ranging from merely keeping vigilant to avoiding the metro system, bus stops or crowds.The warnings come after a string of deadly attacks on the country's security forces since the July 20 Suruç suicide bombing in southeastern Turkey, which killed 32 people and injured more than 100.Ankara has responded to the bloodshed by arresting more than 1,300 suspected supporters of groups such as ISIS and the PKK and significantly stepping up security measures.However, in Istanbul today, many visitors remained positive about the situation.One couple from Johannesburg, South Africa, Nadia Reyneke, 24, and Dean Bryson, 26, are in Istanbul for four days, taking a break from their jobs as teachers in South Korea.Speaking to Anadolu Agency (AA) in Istanbul's tourist hub of Sultan Ahmet, just a few minutes' walk from where a police officer was killed by a suicide bomber in January, the couple said: "We are coming from South Africa, so we know if you go to the parts where it is bad, you are going to get in trouble, but we feel like you can't miss out on the history and beauty of the country just because something might happen.""It is like saying you are not going to travel on an airplane because of possible aircraft problems," they added.Another tourist, Gianluca Nazzoni, is a 52-year-old manager of a chemical company from Bergamo, Italy. Visiting Istanbul with no less than 10 family members, he said that when he heard the warnings he had questions but then "decided to come anyway.""We thought if something is going to happen, it is going to happen anyway," Nazzoni said. The family will go on to the southwestern Aegean coast after spending four days in Istanbul.However, according to Turkey's Culture and Tourism Ministry, foreign arrivals were down in June.The ministry's report said that the number of foreigners arriving in Turkey in June 2015 was 4,123,109, a 4.89 percent decrease from the same month in the previous year.Speaking to AA, a first-time visitor to Istanbul, 45-year-old New Yorker Michael Maguire who works in finance, said that he had not heard any particular warning but had heard about the Suruç suicide bombing in Şanlıurfa.Maguire, who has spent four days in Istanbul so far, said he had not thought about canceling his trip "because, like in the United States, things occur all the time."Giving examples of terrorist attacks in the U.S. Maguire added: "It didn't stop me living in the U.S., so it is not going to stop me traveling to other parts of the world. That is part of terrorism - to stop people traveling and create fear; it doesn't stop us," he said.