Missouri jail inmates used pancake batter and toothpaste to cover a hole they made to allow a female inmate to slide in and join a male inmate.
Now steel plates are being added to the Missouri jail's interior walls.
The hole at the Scott City Jail was discovered this weekend, said police Chief Don Cobb. He said inmates removed a block from the wall, after making a digging tool with a nail, a wire from a light fixture and a toothbrush.
The mixture of pancake batter and toothpaste looked like mortar, he said.
Prisoners will stay in a county jail until a security check is completed at the city building.
The city jail's exterior walls already are reinforced with steel to prevent inmates from escaping, Cobb said.
"Unless they can smuggle in an arc welder, they aren't getting through that," he said.
The Chinese military believe that Beijing and Moscow must resist pressure from Washington together