Safety and security should be of paramount concern to any visitor to the Philippines. It is vital to be fully informed of threats and developments regarding crime, terrorism and kidnapping before and during a visit to the islands. Vigilance is vital throughout the islands, particularly in Manila, as opportunistic crimes are motivated by circumstances of poverty. Extremist groups have a history of kidnapping foreign tourists, and terrorist bombings have occurred in Manila and Mindanao, targeting transport and public places. Recent explosions in Mindanao have killed and injured many people. Security has been increased across southern Philippines, and many foreign governments have issued warnings against travelling to Mindanao. Terrorist groups have also threatened to attack passenger ferries and other vessels, particularly those operating from Mindanao. The threat of terrorism and kidnapping is greatest in central, southern and western Mindanao, Basilan, Tawi Tawi, Jolo and the Sulu archipelago; the FCO, US Department of State and other governments advise against all travel to these areas, and care should also be taken in Palawan and at coastal resorts and tourist centres throughout. There is a high incidence of piracy and armed robbery against ships in and around Philippine waters, and a risk of kidnappings at sea. It is believed that terrorists are continuing with plans to kidnap foreigners from the islands and coastal areas in southern Philippines, putting all boats travelling to and from offshore islands in the Mindanao and the Sulu archipelago, as well as at dive sites at great risk. Safety standards on ferries are low, and rescue services are not very comprehensive. It is advisable to avoid travel off the beaten track, and to leave travel plans with friends, colleagues or relatives. The area is prone to typhoons between July and November, when flooding and landslides can occur; Typhoon Fengshen in June 2008 caused flash floods, landslides and rough seas that has lead to hundreds of deaths.