Yemen's presidential candidate Abd- Rabbu Mansour Hadi (1st L) casts his ballot at a polling station in Sanaa, capital of Yemen, Feb. 21, 2012. More than 10 million eligible voters are expected to cast their ballots at about 29,000 polling stations across Yemen from 8:00 ( 0500 GMT) to 18:00 (1500 GMT), with over 100,000 soldiers guarding the process. However, a string of attacks on election committees flared up in the country's restive southern regions. [Xinhua]