New subway links to the stations are also being made , and it has been proposed to lengthen the Tseung Kwan O Line with a branch line to Tseung Kwan O South , and the Kwun Tong Line as far as Whampoa Garden , also linking with the Sha Tin to Central Link expansion . The interchange between the Tsuen Wan Line and the Kwun Tong Line , the Island Line and the Tseung Kwan O Line , as well as that between the Kwun Tong Line and the Tseung Kwan O Line , are two stations long , allowing cross-platform interchange wherein a passenger leaves a train on one side of the platform and boards trains on the other side of the platform for another line . For example , when passengers are traveling on the Kwun Tong Line towards Tiu Keng Leng , getting off at Yau Tong would allow them to switch trains across the platform for the Tseung Kwan O Line towards North Point .