It also operated two smaller buses for an intra-Valletta route only and 61 nine-metre buses, which were used to ease congestion on high-density routes. Overall Arriva Malta operated 264 buses. On 1 January 2014 Arriva ceased operations in Malta due to financial difficulties, having been nationalised as "Malta Public Transport" by the Maltese government, with a new bus operator planned to take over their operations in the near future. The government chose Autobuses Urbanos de León as its preferred bus operator for the country in October 2014. The company took over the bus service on 8 January 2015, while retaining the name "Malta Public Transport". It introduced the pre-pay 'tallinja card'. With lower fares than the walk-on rate, it can be topped up online. The card was initially not well received, as reported by several local news sites. During the first week of August 2015, another 40 buses of the Turkish make "Otokar" arrived and were put into service. From 1883 to 1931 Malta had a railway line that connected Valletta to the army barracks at Mtarfa via Mdina and a number of towns and villages. The railway fell into disuse and eventually closed altogether, following the introduction of electric trams and buses. At the height of the bombing of Malta during the Second World War, Mussolini announced that his forces had destroyed the railway system, but by the time war broke out, the railway had been mothballed for more than nine years. Malta has three large natural harbours on its main island:  There are also two man-made harbours that serve a passenger and car ferry service that connects Ċirkewwa Harbour on Malta and Mġarr Harbour on Gozo. The ferry makes numerous runs each day. Malta International Airport (Ajruport Internazzjonali ta' Malta) is the only airport serving the Maltese islands. It is built on the land formerly occupied by the RAF Luqa air base. A heliport is also located there, but the scheduled service to Gozo ceased in 2006. The heliport in Gozo is at Xewkija. Since June 2007, Harbour Air Malta has operated a thrice-daily floatplane service between the sea terminal in Grand Harbour and Mgarr Harbour in Gozo. Two further airfields at Ta' Qali and Ħal Far operated during the Second World War and into the 1960s but are now closed.