In the UK this is pretty common. I know a lot of muslim people who say they are British Asians.
Yeah, Asian has a different meaning in the UK than the US. In the UK it refers primarily to the people of South Asia, from countries such as India, Pakistan and Bangladesh.
Whereas in the US asian tends to refer to East/Southeast Asia, including countries like China, Japan, Korea and Malaysia.
This difference makes sense if you consider the historical connections between Britain and 'Asia' and the difference between the US's involvement with 'Asia'.
The UK had a strong colonial connection with the Indian subcontinent effectively ruling most of modern India, Pakistan, Bangladesh and Nepal. As a result this part of Asia was more strongly present in our culture.
The US however had relatively little connection to western Asia but instead has had a closer tie to east Asia. The biggest connection was the large influx of chinese immigrants in the 1800s during the construction of the transcontinental railways. Then later on the US was heavily involved in the 1900s with East Asia via war in the Pacific against Japan in WW2, followed by the Korean and Vietnam wars. And in recent years the big rival of the US has been China. So as far as American culture is concerned the main image of Asia is that of the East, which in the UK would historically be referred to as 'the Orient' or 'Far East', although these days those terms aren't considered as politically correct.
