It was suspected by CNN that the police used force during the protest. Here is the evidence.
One of the organization in the HK media industry, Commercial Radio Hong Kong News (CRHKNEWS) , has recorded a video which proves that the police used violence to anyone regardless their identity , such as reporters. The link of the post and video are as follow. https://zh-hk.facebook.com/crhknews/videos/2420096214722357/
The translation of the caption:
警方晚上在金鐘正義路驅散示威者期間，本台記者在採訪期間多次表明身份，受警員多次推撞，記者並無大礙。
While the police were dispersing protesters at Justice Drive at Admiralty, our reporters had been stating their identity repeatedly ,but were still pushed and confronted by the police for several times. The reporter is safe now.
The attached video (with subtitles) posted by CRHK NEWS on facebook shows the conversation between the police, protesters and reporters.
我同朋友夾手夾腳加左英文字幕同打埋email format
如果有咩錯麻煩各位巴絲補充同指證
同時send埋email俾cnn嗰邊同dm佢地啲記者啊
最後請咁多位巴絲傳開同幫手推一推！
唔該晒
https://youtu.be/OBvasPUwGOE