Fifa opened a disiciplinary investigation into fans booing the Chinese national anthem prior to the Hong Kong-China clash at Mong Kok Stadium last Tuesday. The Hong Kong Football Association confirmed in a statement that they received a letter from the world governing body and were asked to provide a statement and evidence regarding the incident that took place before the match, which ended up a 0-0 draw and dealt a heavy blow to China's chances of qualifying for the 2018 showpiece. The HKFA is requested by Fifa to provide a statement and any supporting evidence that the HKFA may consider as relevant to the present case by December 1 HKFA statement "Today, the HKFA has received an official letter from Fifa announcing that disciplinary proceedings have been opened against the HKFA. The letter also confirmed that the HKFA appeared to be in violation of the Fifa Regulations (article 65 ff of the Fifa Disciplinary Code)," the statement said. READ MORE: Keep politics out of sport? Heaven forbid, as Hong Kong v China showed "The incident referred to is the booing of the national anthem prior to the match. The HKFA is requested by Fifa to provide a statement and any supporting evidence that the HKFA may consider as relevant to the present case by December 1." The HKFA also said the final decision will be released by Fifa by the end of December. Read all of our World Cup 2018 Asian qualifying coverage here The local governing body was fined by Fifa after fans booed the Chinese anthem and threw a paper cup onto the pitch in another World Cup qualifying match against Qatar in September. The HKFA said after being fined last time: "Fifa has warned the HKFA that any further infringements will lead to more severe sanctions." The most severe punishment could see Hong Kong stripped of points or even disqualified from the World Cup qualifiers.