BANGKOK, Nov 25 (Reuters) - About 40 anti-government protesters forced their way into Thailand's Finance Ministry on Monday, as thousands of demonstrators marched to 12 buildings in Bangkok seeking to overthrow Prime Minister Yingluck Shinawatra.

Shortly after the protesters burst into the Finance Ministry, the building's power was cut, a Reuters witness said.

More than 30,000 protesters chanted "Get Out!" as they spread across the city on Monday to government offices, military and naval bases and state television channels. (Reporting by Kittipong Thaicharoen; Writing by Amy Sawitta Lefevre; Editing by Jason Szep and Robert Birsel)