Disappointed users of Apple's newly released iPhone 4S have gained a promise of relief after the company broke its silence regarding the growing complaints about the smartphone's poor battery life.

Apple Inc. issued an official statement on Wednesday, saying that the battery's drastic drain was caused by bugs in the new operating system - iOS 5.

A small number of customers have reported lower-than-expected battery life on iOS 5 devices, Apple spokeswoman Natalie Harrison said in a statement. The Cupertino, Calif.-based tech giant promised to solve the problem.

We have found a few bugs that are affecting battery life, and we will release a software update to address those in a few weeks, Harrison added.

Apple had claimed that the iPhone 4S would deliver battery life of up to eight hours on 3G networks and up to 14 hours on 2G (GSM) as talk time. The standby time was claimed to be up to 200 hours and video playback time was promised up to 10 hours.

Unhappy iPhone 4S users took to social networking sites like Facebook and Twitter to post their grievances, saying that they did not have the claimed power back-up capabilities promised by the device's makers.

Some tech bloggers had already blamed the poor power back-up on the iPhone as a problem with the iOS5. It was pointed out that some of the OS's newer features ran constantly in the background, even when they were not required to do so, thereby draining even more of the smartphone's battery charge.

Also Read: Apple's iPhone 4S Battery Drain: 4 Ways to Fix the Problem