Video from the scene showed hundreds of passengers having to lower themselves onto the tracks after the accident, which happened at about 8.30am.
The MTR Corporation said at about 8.45am that trains would not run between Hung Hom and Mong Kok East for the time being. Hung Hom Station has been closed.
Trains between Mong Kok East and Lo Wu are running at six-minute intervals, while trains to Lok Ma Chau are running every 18 minutes.
Services on the West Rail Line are also facing “severe delays”.
Last updated: 2019-09-17HKT 09:01