were transferred to the primary school of Ħamrun. Demand for postal services increased drastically after the war, and many new post offices were established in towns and villages between the 1950s and the 1980s. The first postage meter was installed in Malta in 1961. Malta became independent in 1964, and the country was accepted into the UPU on 21 May 1965. The Parcel Post Office moved to a new building in Victory Square in Valletta on 12 November 1963. Palazzo Parisio remained in use by the postal authorities until 4 July 1973, when the GPO moved across the street to Auberge d'Italie and the Central Mail Room, the registered letter branch and the Poste Restante moved to the former Garrison Chapel (a building now housing the Malta Stock Exchange). While it was the GPO, parts of Auberge d'Italie also housed other government departments. Following the murder of Karin Grech by a letter bomb in 1977, mail addressed to people who were perceived to be at risk of a similar attack was checked for explosives. Once an item was certified as harmless, a marking with the letter X was applied to it before being delivered to the recipient. Such markings are known as "Karin Grech crosses" by philatelists. Alphanumeric postal codes were introduced in Malta in 1991. Posta Ltd (1995–1998) On 1 October 1995, the private limited company Posta Ltd was set up to run the General Post Office. This was done after the British Postal Consultancy Service made a recommendation in 1994 that the postal service should be run commercially. In 1996, the company made losses when sending bulk mail to Germany after the latter increased its tariffs. Posta Ltd had signed a contract with the phantom company Euromail Ltd which did not take into consideration the rate increase, and the latter profited from the former's losses. In October 1997, the company moved to new premises at 305, Qormi Road in Marsa, and the Parcel Post Office, Central Mail Room and Philatelic Bureau were transferred there from Valletta. MaltaPost (since 1998) The public limited company MaltaPost plc was established on 16 April 1998, and it took over operations of Malta's postal service on 1 May of the same year. On 31 January 2002, MaltaPost was partially privatized when the government sold 35% to Transend Worldwide Ltd, a subsidiary company of New Zealand Post. In September 2007 the government sold 25%