Apple Inc is recalling 64 and 128-gigabyte flash storage drives used in Macbook Airs as it could lead to the laptops failing to operate, Apple said on its website Sunday.

Affected users were advised to back up personal data and files before getting the drive replaced at Apple Stores or authorized sites on the Chinese mainland.

Replacement times depend on stocks and the number of applicants requiring a replacement drive, an employee at an Apple store in Shanghai said yesterday.

"The system may fail with the drives used in Macbook Airs sold between June 2012 through June 2013," Apple said on its website without providing details.

The SSD, or solid state drive, represents the latest computer drive technology. They are faster and more energy efficient.

Users can test computers through an update called MacBook Air Flash Storage Firmware Update 1.1. It will tell users if their drive is affected.

Apple warned owners of these laptops not to download any new operating systems.

Several customers inquired about the problem at Apple's store on Huaihai Road yesterday afternoon but none of them needed a replacement drive, Shanghai Daily learned.

Apple also has stores on Nanjing Road and in the Lujiazui finance zone of the Pudong New Area. Local Apple authorized service providers are also offering free drive replacements.

In 2011, Apple recalled MacBook MagSafe power adapters because the faulty devices were prone to splitting.