US Republican presidential hopeful and former Massachusetts Gov. Mitt Romney is seen through a window as he speaks during a campaign rally at the Tri-City Christian Academy in Chandler, Arizona. (AFP)

Firemen rescue wounded passengers from a commuter train after a collision in Buenos Aires. A packed train slammed into the end of the line in Buenos Aires' busy Once station, injuring over 300 morning commuters, Argentina's transportation secretary said. (AP)

A protester with Yemen's flag painted on his body shouts slogans during a rally in Sana'a demanding the prosecution of President Ali Abdullah Saleh. (AP)

A monk participates in a debate as part of Tibetan New Year celebrations at a temple in Langmusixiang, Sichuan Province. (Reuters)

Protesters run as smoke raises from a burning truck during an anti-US demonstration at a NATO military base in Jalalabad, east of Kabul, Afghanistan. (AP)

Statues of Buddhist monks near a temple in Payathonzu, near the Burmese border with Thailand (Reuters)