Beijing Capital International Airport (BCIA) will close from 7:59 pm until midnight during the opening ceremony of the Olympic Games on Aug. 8.

More than 20 flights from Shanghai to Beijing will be affected by the four-hour closure. Those flights will either be canceled or delayed.

All flights will return to schedule the following day.

There are only 27 flights available from Shanghai to Beijing on Aug. 8 on Ctrip.com, while 43 are available on Aug. 7 and another 45 on Aug. 9.

The latest Air China flight departs Shanghai for Beijing at 2:55 p.m. on Aug. 8.

China Eastern Airlines and China Southern Airlines have three flights that will take-off after 10 pm on Aug. 8 and arrive in Beijing early on Aug. 9.

China Eastern officials said it was not taking bookings for flights from 3 pm to 10 pm on Aug. 8. While flight schedules for Aug. 8 may be adjusted at any time, the airline has pledged to inform passengers of any changes.

Because Shanghai's two airports will handle a lot of Olympics-related business, other flights may be adversely affected.

From Jul. 20, the Beijing airport will use explosive-detection devices at the entrances to its three terminals. Police will check all luggage for explosive materials.

Also from Jul. 20, airports in 18 cities and regions, including Shanghai, will launch extra security checks.