In the 21st century, property and real estate development in the city has boomed, with a dramatic increase in new hotels and shopping centres, fuelled by the policies of Mohammed VI of Morocco, who aims to increase the number of tourists annually visiting Morocco to 20 million by 2020. In 2010, a major gas explosion occurred in the city. On 28 April 2011, a bomb attack took place in the Jemaa el-Fnaa square, killing 15 people, mainly foreigners. The blast destroyed the nearby Argana Cafe. Police sources arrested three suspects and claimed the chief suspect was loyal to Al-Qaeda, although Al-Qaeda in the Islamic Maghreb denied involvement. In November 2016 the city hosted the 2016 United Nations Climate Change Conference.