The first phase was to meet with the local managers. The tone of the interview was friendly and casual, with some of the regular interview questions thrown in later. The second phase was an online assessment test, including the command of English language (think GRE), behavior math and logic. Not too difficult, although some seemed tricky, like 4000% / 2500%. Also, it seemed that some math question did not offer a correct answer on multiple choice, but maybe I just got it wrong ;). It doesn't seem to be necessary to get everything right (or you may seem overqualified), but rather the HR will gauge your overall aptitude.
The last phase was a meeting with the managers and HR, with questions linked to the results for the online test. Expect typical interview questions, situation based, etc.
Overall I found the interview quite reasonably easy if you do your homework and prepare some situations from your past.