Several small bombs exploded in Mexico City early Monday, damaging several buildings but causing no reported injuries.
Authorities say three nearly simultaneous blasts occurred just after midnight. The explosions damaged the Federal Electoral Tribunal and a bank, and destroyed a portion of the headquarters of Mexico's former ruling party.
The Institutional Revolutionary Party, or PRI, dominated Mexican politics for more than 70 years, but is now in opposition.
Mexican news media report that police deactivated a homemade explosive device at a second bank near the offices of the Electoral Tribunal.
So far, there have been no claims of responsibility for the bombs.
Violent attacks similar to today's bombings have occurred periodically in Mexico, and they are usually attributed to leftist groups. Targets generally include international banking institutions and other commercial centers.Some information for this report was provided by AFP, AP and Reuters.