Those extradited include suspects in two sets of killings in 2011 involving Americans.

The group of 13 includes people charged or suspected in two 2011 crimes involving Americans - an attack on immigration agents in San Luis Potosi and the killing of consulate workers in Cuidad Juarez.

The move was part of a new coordination effort between Mexico and the United States to fight organized crime, a US Justice Department statement said.

Their extradition occurs weeks after the jailbreak of kingpin Joaquin "El Chapo" Guzman, which is seen as having put a strain on Mexico's relations with the United States.

"My guess it is that they're probably starting to make amends for El Chapo," Mexican security expert Alejandro Hope told the AP news agency.

The US had again filed an extradition request for Guzman about two weeks before his escape. His lawyer said his escape was a direct result of learning that the extradition was imminent.

Guzman slipped out of prison through a tunnel on July 11, not even a year-and-a-half since he was captured after years on the run. The US had sought his extradition after his arrest in February 2014, but Mexico refused, trying him at home instead.

Mexican officials would not comment on whether the timing of the extraditions had anything to do with Guzman's disappearance.

"My guess is that they're probably starting to make amends for El Chapo," Mexican security expert Alejandro Hope told AP.

jr/bw AP, AFP, Reuters)