Paraguay has apparently bought the relatively new Norinco CQ 5.56, M4A1 clones.
The caption of the above photo, translated from Spanish:
Soldiers of the Joint Detachment of Empleo Inmediato (DECEI) marching past with carbines Norinco CQ-M4 of 5.56 mm Are copies of Colt M-4A1 made in China and equipped with viewfinders of not known model. The DECEI depends on the Commando of Special Troops of the Army.
According to Wikipedia:
This variant introduced in the year 2006 in several Defense expos worldwide, including the MILIPOL, is a copy of the American M4A1 assault carbine. It features a telescoping stock, a removable carrying handle mounted on a Picatinny rail, and a 368,3 millimetres (14,5 inches) barrel. The CQ Type A carbine variant is claimed to be able to stabilize both M193 “Ball” and SS-109/M-885 variants of the 5.56 mm cartridge, as would be expected from a rifle with a 1:9 barrel rifling twist. It will quickly accept the installation of grenade launchers due to the quick attachment/detachment handguard design and to the step-cut barrel.
H/T: china police @ MP.net