Scores of weapons including machine guns and grenades have been found at a high-security prison in Mexico.
The discovery was made as 300 prisoners were being transferred from three state detention facilities in Chihuahua state to other prisons. Most of the weapons were found at a prison in Ciudad Juarez. Ammunition and mobile phones were also confiscated.
"Seven rifles were discovered, among them AK-47s, and some magazines and drum magazines," said Eduardo Guerrero, Chihuahua state prosecutor.
"We've also confiscated 10 handguns of various calibres as well as 19 improvised shotguns, 14 magazines, 2,136 rounds of ammunition, three grenades, 422 sharp weapons and 76 cellphones," he added.
Prisons in Mexico are filled with rival gangs from powerful drug cartels. Violence regularly boils over in the prisons. In February, 44 people died and 30 prisoners escaped during a gang battle at an overcrowded prison in the state of Nuevo Leon.
Around 7,000 people have also died over the past five years in relation to drug cartels in Ciudad Juarez.