Amnesty International has urged the Syrian authorities to investigate the killing of a 14-year-old boy and the wounding of dozens of other people, after security officials opened fire on a Kurdish New Year celebration on 21 March.The organization has received reports that many of those injured in clashes with law enforcement officials, are being held under tight security in hospital and are being denied access to their relatives.The incident happened in the north-eastern city of Ar Raqqah on Sunday, as an estimated 5,000 Syrian Kurds gathered to celebrate Nawrouz, the Kurdish New Year.The gathering was organized by the Democratic Union Party (PYD), a Kurdish minority political party unrecognized by the Syrian authorities.Violence broke out when law enforcement officials objected to people holding up PYD flags and pictures of 'Abdullah Öcalan, leader of the Kurdistan Workers' Party in Turkey (PKK), who is imprisoned in Turkey.Police used tear gas and pumped water at the crowds then opened fire with live ammunition when some of the demonstrators threw stones at them.Fourteen-year-old Mohammed Haider Iben 'Omar, was killed. Syrian-Kurdish human rights organizations claim that he may have died due to excessive use of force.On Tuesday, Political Security officers delivered his body to his family and supervised the burial. It is reported that the family was not permitted to hold a funeral.Many of those injured during the clashes were taken to Ar Raqqah National Hospital, which has since been surrounded and placed under guard by the security forces.To date, only two of the injured have been permitted to receive visits from their families, prompting concern that the rest may be at risk of torture or other ill-treatment.The Syrian authorities have not commented on the events in Ar Raqqah and no investigation is known to have been opened into allegations that law enforcement officials used excessive force.Amnesty International urged the Syrian authorities to conduct an immediate independent investigation into the use of lethal force by law enforcement officials and whether this constituted excessive use of force in breach of recognized international standards.The organization said that any officials responsible for using excessive force should be held to account.It also urged the authorities to allow all those injured or detained in connection with the 21 March events to have immediate access to their families, to legal counsel of their choice and to any medical care that they require.The Kurds comprise up to 10 per cent of the population of Syria and live mostly around the city of Aleppo in the north of the country and the al-Jazeera region in the north-east.These predominantly Kurdish areas lag behind the rest of the country in terms of social and economic development. Syrian Kurds are subject to identity-based discrimination, including restrictions on the use of their language in schools and the expression of their culture, such as bans on producing and circulating Kurdish music.Nawrouz is one of the main events celebrated by members of the Kurdish minority in Syria, and Kurdish political parties usually hold public gatherings to deliver speeches and sing songs in the Kurdish language.