The search engine seems to have run afoul of the Myanmar government, a military dictatorship with a history of blocking Internet access.
Gmail and Gtalk were banned June 22 and 23, according to users on Planet Forums. The users report there may be a few ways to work around the block.
Representatives from Google have not returned requests for more information.
The Google sites are apparently being blocked by Myanmar's largest ISP, Bagan Cybertech. The company has not returned a request for comment.