Mexico's murder rate is getting significantly worse again, after a few years during which the killing had begun to fall off.

According to official figures released this week, the number of murders in Mexico during the first half of this year was around 15 percent higher than in the same period of 2015.

The 10,301 killed from January through June, an average of 57 per day, is still about 10 percent less than when murders reached a peak during 2011.

But the upward trend does indicate the country's horrific drug wars — that intensified after the launch of a major anti-organized crime offensive by President Felipe Calderón a decade ago — are still far from being brought under control.

"It is a very worrying trend," said prominent Mexican security analyst Alejandro Hope. "We're fast approaching the levels we experienced during the late months of the Calderón administration."

President Enrique Peña Nieto, who took office in December 2012, has previously used the fall off in homicides to back the claim that his government is wresting power from the drug cartels. Government officials continued to do this even after the drop plateaued last year.

Much of that fall in the first years of Peña's administration was due to the end of the bloodbath in the border city of Ciudad Juárez that had averaged about eight homicides a day. That dramatic drop began before President Peña took office, with many locals claiming it had less to do with the success of security strategy and more to with the victory of one of the city's warring cartels over the other.

Now, the reversal of the national trend, shows that while things remain relatively tranquil in Juárez, they have got worse in many other parts of the country.

Hope, the security analyst, blames the renewed violence on "really nasty fights" between the larger cartels, and "increasing violence," between smaller gangs.

The two states with the highest number of homicides, Guerrero and Mexico State, are caught up in particularly vicious turf wars between numerous small scale gangs.

The border state of Tamaulipas is currently in the midst of infighting between two factions of the Zetas cartel. The Vieja Escuela Z, or Old School Zetas, are at war with the Cartel del Noroeste, or the Northeastern Cartel, led by a young relative of jailed former Zetas leader Miguel Treviño.

Hope also attributes the hike in killing to some cartels "smelling weakness in Sinaloa" in the wake of the rearrest of the Sinaloa cartel's infamous leader Joaquín "El Chapo" Guzmán.

Other criminal groups reportedly now trying to muscle in on Sinaloa territory include the fast growing Jalisco New Generation cartel, the remnants of the once powerful Beltrán Leyva cartel, and a group headed by the recently freed gangster Rafael Caro Quintero.

These conflicts could explain rising murder rates in states such as Colima, Chihuahua, Northern Baja California, Guanajuato, and Sinaloa itself.