Ten tourists were killed and 15 people wounded in Istanbul’s historic Sultanahmet Square in a suicide attack on 12 January. The explosion was in one of the city’s most popular tourist areas, close to the Obelisk of Theodosius, the Blue Mosque and the Museum of Turkish and Islamic Arts. Hagia Sophia, the former church turned mosque that is now a museum, is within walking distance. The bomber had entered Turkey from Syria posing as a refugee, Turkish authorities said. The attack is blamed on Isil extremists. The Istanbul authorities have increased security at historic sites and in crowded areas.