TWO men armed with a knife yesterday tied up and robbed a woman of $575,000 in cash and valuables at her Tsim Sha Tsui flat. The bandits grabbed the woman by the neck in the lift lobby and forced her back inside her flat where she was bound with nylon stockings. The thieves then ransacked her home and stole a $480,000 diamond watch, two diamond rings worth $46,000, a mobile telephone worth $21,000, US$100 (HK$770) and 20,000 yuan (HK$26,940). Police are hunting two men aged between 29 and 30, about 1.65 metres tall. One was wearing a purple suit and the other a brown suit.