Brazil is politically stable with no natural enemies and no terrorist activities. In metropolitan areas, however, petty crime is a fact of life. Rio in particular is regarded as one of the most crime-ridden cities in the world and, although violent crime is generally limited to the slum areas, foreigners are advised to take precautions. Visitors should not attempt to visit slum areas unless on a guided tour. However violent crime is on the increase due to the establishment of drug and criminal gangs around Rio and Sao Paulo. Muggings, often involving firearms, are frequent and visitors should dress down and conceal cameras, and avoid wearing jewellery and expensive watches. Valuables should be deposited in hotel safes. The threat of personal attack is lower outside the main urban centres, but incidents do occur, and women should be aware that sexual assaults have been reported in coastal holiday destinations. Beware of unofficial taxis and those with blacked-out windows and be particularly careful on public transport in Rio, Recife and Salvador. Armed criminals intercepted a taxi carrying foreigners at night from Antonio Carlos Jobim International Airport to central Rio in May 2006; incidents like this occur at random along this road, particularly at night.