Factbox: Worst attacks in Mexico's drug war

MONTERREY, Mexico (Reuters) - Mexican security forces found the body of a slain mayor near Monterrey, Mexico's richest city, on Wednesday, days after he was abducted by suspected drug hitmen.

Below are some of the worst attacks since President Felipe Calderon took office in December 2006 and declared war on powerful drug cartels. Some 28,000 people have been killed in drug-related violence since then.

* Aug 18, 2010 - The body of the mayor of Santiago, a colonial tourist town near Monterrey, was dumped on a rural road, two days after he was taken from his home. Calderon condemned the killing of Edelmiro Cavazos, the latest attack on public officials in an escalating drug war.

* July 18, 2010 - Gunmen burst into a birthday party in the northern city of Torreon, using automatic weapons to kill 17 party-goers and wound 18 others. Mexican authorities later said those responsible were incarcerated cartel hitmen who were let out of jail by corrupt officials. The killers allegedly borrowed weapons and vehicles from prison guards and later returned to their cells.

* July 15, 2010 - A 22-pound (10-kilo) car bomb killed four people in Ciudad Juarez in a blast that was detonated by cell phone, the first such attack since Calderon took office.

* June 28, 2010 - Suspected cartel hitmen shot and killed a popular gubernatorial candidate in the northern state of Tamaulipas in the worst cartel attack on a politician to date. Rodolfo Torre, 46, and four aides from the opposition Institutional Revolutionary Party, or PRI, were ambushed on their way to a campaign event for the July 4 state election.

* June 11, 2010 - Two dozen heavily armed gunmen burst into a drug rehabilitation clinic in the northern city of Chihuahua and killed 19 addicts, ranging in age from 18 to 25.

* March 28, 2010 - Gunmen in northwestern Durango state killed 10 people, as young as 8 years old, after the pick-up truck they were traveling in sped through a roadblock on an isolated highway in the drug-producing "Golden Triangle" region.

* March 13, 2010 - Hitmen killed three people linked to the U.S. consulate in Ciudad Juarez in March, provoking "outrage" from U.S. President Barack Obama.

* January 31, 2010 - Suspected cartel hitmen killed 13 high school students and two adults at a party in Ciudad Juarez.

* September 15, 2008 - Suspected members of the Zetas drug gang tossed grenades into a crowd celebrating Mexico's independence day in the western city of Morelia, killing eight people and wounding more than 100.