The ceremonies -- which traditionally include all-night vigils in cemeteries and colorful altars with food and drink -- are taking place as the fifth anniversary of a crackdown on organized crime approached with violence ongoing.

Mothers of missing Central American migrants traveled to San Fernando, in northeast Tamaulipas state near the US border, to set up an altar Wednesday -- the actual Day of the Dead -- for 72 migrants massacred there in August 2010.

Authorities blamed those killings on the Zetas drug gang -- former hitmen who are now considered one of the most brutal and powerful drug gangs, accused in killings and kidnappings across Mexico and Guatemala.

The leftist Democratic Revolutionary Party (PRD) dedicated its Day of the Dead offering to 13 journalists killed in Mexico this year alone.

Mexican poet Javier Sicilia, who became an anti-violence activist after the brutal killing of his son, led 200 people in silence Monday night to leave crosses at the Angel of Independence monument in Mexico City.

They paid homage to almost 45,000 people killed in suspected drug-related violence since the government of President Felipe Calderon started the military clampdown in December 2006.

In southeastern Veracruz state, where 35 bodies were recently dumped on a busy road in broad daylight, around 300 people left offerings to the victims of violence at the cathedral in state capital Xalapa.

Families prepared altars and graves decorated with orange marigolds across the country, from traditional sites like western Patzcuaro -- where 140,000 tourists were expected for lakeside ceremonies -- to Mixquic, outside Mexico City, in a tradition dating to pre-Hispanic times.

UNESCO in 2003 named the Day of the Dead, or Dia de los Muertos, as an Intangible Cultural Heritage of Humanity.