Mexico drops generals' drug charges
Prosecutors in Mexico have dropped charges against a group of senior army officers who were accused of having links to a drugs gang.
The officers, including three generals, were arrested last year and kept in a maximum security jail.
They were accused of protecting members of the Beltran Leyva cartel in a case that reportedly relied on evidence from detained drug traffickers.
Judges said the witness testimony was not enough to prove the charges.
Two people in a witness protection programme, known under the code names of Jennifer and Mateo, had accused the soldiers of links with the Beltran Leyva cartel.
Generals Roberto Dawe, Ricardo Escorcia and Ruben Perez, and Lt Col Silvio Hernandez Soto, were all arrested last year. They were set free this week.
The most high-profile officer implicated in the case was retired Gen Tomas Angeles Dauahare, who was freed from jail in April.
The men are among the highest-ranking officers to be arrested and charged in recent years.
Mexican troops played a key role in tackling the drug gangs under former President Felipe Calderon from 2006 to 2012.
Gen Angeles was assistant defence minister from 2006 to his retirement in 2008.
Gen Escorcia was the head of the military in Morelos state, which was considered Beltran Leyva territory. He stepped down in 2010 when he reached retirement age.
Gen Dawe commanded a military base in western Colima state, an important trafficking route.
Col Hernandez Soto retired from the army in 2002 and became a senior police commander in Sinaloa state.
The soldiers were charged with "organised crime to further drug-trafficking", though the details of the accusations were unclear.
All the men denied the charges.
The Beltran Leyva gang began to fragment in 2009 after its leader, Arturo Beltran Leyva, was killed in a shootout with marines.
Drug-related violence has killed tens of thousands in Mexico since 2006.