HONG KONG, June 17 (Reuters) - Hong Kong police arrested five directors ofthe Apple Daily newspaper early on Thursday morning, including its editor-in-chief, the media outlet said, in the latest blow to the newspaper"s jailed owner Jimmy Lai. Hong Kong Police"s National Security Department said in a statement that five directors of a company had been arrested on suspicion of collusion with a foreign country or with external elements to endanger national security. It said only that the five included four men and a woman aged between 47 and 63. It did not provide other details. Apple Daily said five of its directors, including editor-in-chief Ryan Law, chief executive officer Cheung Kim-hung, Chief Operating Officer Chow Tat-kuen, Deputy Chief Editor Chan Puiman and Chief Executive Editor Cheung Chi-wai had all been arrested in morning raids. The newspaper said that at about 7:30 a.m. local time around 100 officers arrived at its headquarters in Tseung Kwan O in the New Territories district and cordoned off the area. National security police said in a statement that officers had searched a media company in Tseung Kwan O with a warrant that covers "the power of searching and seizure of journalistic materials." The operation was ongoing and aimed to gather evidence for a case related to suspected contravention of the security law. The move is the latest blow to Apple Daily after authorities last month directedjailed tycoon Lai"s shares in Next Digital (0282.HK) , publisher of the newspaper, to be frozen. In May, Reuters reported that Hong Kong"s security chief sent letters to Lai and branches of HSBC and Citibank threatening up to seven years in jail for any dealings with the billionaire"s accounts in the city. read more Lai was arrested in August last year and later charged under the national security law imposed by China on its freest city. The pro-democracy activist"s assets were also frozen under the same law. He has been in jail since December after being denied bail in a separate national security trial. He faces three charges under the new law, including collusion with a foreign country. Reporting by Tony Munroe; Editing by Jacqueline Wong