To safeguard aviation security, Hongkong Post does not accept the sending of air mail items (including Speedpost) that contain dangerous articles such as perfumery products, lighters and lithium batteries. Hence, all mail items entering the Air Mail Centre are subject to x-ray screening. Recently, there is an increasing number of air mail items detected to contain suspected dangerous articles, in particular, lithium batteries, which lengthens the screening process. In this connection, air mail registration service, iMail service and Bulk Air Mail service may be subject to delay. Any inconvenience caused is much regretted.