SHANGHAI--All stores in the subway system of this Olympic co-host city suspended business on Tuesday under a government order to ensure a smooth Olympic Games.

More than 1,000 shops at some 70 stations are affected. Even vending machines have been closed, according to Shanghai Shentong Metro Co., Ltd, the subway operator.

The suspension will last for a month, although the exact date for resuming normal business has yet to be decided by the local authorities. The city has also not announced any compensation measures so far.

Many shops held sales over the past several days ahead of the shutdown.

The city, which will host 12 Olympic football matches from August 8-24, has stepped up security measures, such as setting up checkpoints at transportation facilities, in preparation for the sports event.