“市民报警都无法接通”就证明警方没有接到一个报警电话、不知道元朗地铁站发生了大批黑社会白衣人暴力对民众大打出手所以没有出警？你能用证据说明哪些人提前就知道会有元朗闹事？说说清楚这些人知道说明了什么？

At around 10:30 pm, about a hundred white-shirted assailants appeared at Yuen Long railway station and attacked commuters in the concourse indiscriminately, on the platform and inside train compartments.[19][20] Two police officers arrived at 10:52 pm.[17] However, they left the station as they judged that they were outnumbered by the assailants[20] and did not have sufficient gear, according to the police.[21] Thirty police officers arrived at the station at 11:20 pm, but the assailants had left.[21] Due to the violence, trains bypassed Yuen Long station between 10:56 pm and 11:19 pm,[22] and the station was ordered closed at 11:55 pm.[16] However, after midnight, white-shirted assailants forced open the station's shutters to launch a second wave of attacks on passengers; no police officers were at the scene then.[21] In all, at least 45 citizens were reported injured,[23] including Legislative Council member Lam Cheuk-ting and two reporters; one other journalist had their equipment smashed.[24][25]

Citizens made calls to the emergency hotline upon seeing the armed group assembling at around 7:00 pm, and an MTR spokesman said the first call by the MTR to the police was made at around 10:45 pm, but police officers arrived more than three hours after initial calls for help were made.[26][27] The local police call centre received hundreds of calls between 10 pm and midnight,[28] and some citizens could not connect to the reporting hotline.[29] The management of Yoho Mall, a shopping mall next to Yuen Long station, also attempted to call the police but they could not get in touch with them.[23] The police station near Yuen Long shut its gate in response to the hundreds that turned up to report the incident.

https://en.m.wikipedia.org/wiki/2019_Yuen_Long_violence