Twelve police officers have been killed in the central Mexican state of Guanajuato in the space of a week, reports BBC.
One of those killed was María Sonia Arellano, a decorated officer who was kidnapped along with her husband and son in the city of Irapuato.
While her son and husband were freed, Ms Arellano's body was later found dumped and dismembered.
The powerful criminal group Cartel Jalisco Nueva Generación (CJNG) said it was behind her murder.
The brutal killing of Ms Arellano, who was awarded the order of police merit a few months ago, has caused outrage in Mexico, where murders of members of the security forces are not uncommon.
The 47-year-old was taken from her home by armed men on Tuesday. Her 27-year-old son and her husband, who is also a police officer, were released the following day but she was killed and her body dumped by a rural road.
A message scrawled on cardboard and left next to her body was signed with the initials CJNG.
Ms Arellano was known as "fearless" by her colleagues, who said that she had played a key role in the fight against the local drugs trade and oil theft in her home town of Irapuato.
On social media, many Mexicans paid tribute to the policewoman.
Ms Arellano was not the only female officer to be killed in the city this week.
On Saturday, gunmen opened fire on two officers parked in a patrol car outside a pharmacy. Gabriela Núñez Duarte died of the injuries she sustained in the attack while her police partner was wounded. Another male officer was killed in Irapuato on Thursday.
Irapuato has seen a surge in violence in the past two years as the CJNG tried to wrest control of this mid-sized city from the Santa Rosa de Lima cartel.
The cartels mainly engage in fuel theft from major oil pipelines located near the city as well as selling drugs to locals and extorting businesses.
Gunmen from the CJNG are also thought to have been behind an attack on a police station in Villagrán, 50km (30 miles) to the east of Irapuato on Wednesday.
Hooded men stormed into the police station as the shift change was taking place and shot dead three officers. They abducted four more, whose bodies were later found on the Pan-American Highway.
A video posted on social media showed men dressed in tactical gear with the letters CJNG on their bullet-proof vests driving into Villagrán boasting that "we're entering Villagrán".
Two more police officers were killed in the towns of León and Celaya, also in Guanajuato, on 8 December, bringing the total of officers killed within seven days to 12.
When President Andrés Manuel López Obrador ran for office, he said he would put an end to the "war on drugs" his predecessors had waged, in favour of a strategy for peace. Part of his approach to defeating the powerful criminal cartels was to create a new civilian security force, the National Guard.
However, few have signed up to the new force, some fearing for their lives. And those who have have been deployed to the southern border to deal with the influx of immigrants trying to reach the United States.
The president's strategy has come under intense criticism in recent weeks following an ambush in which nine members of a Mormon community were killed.
There was also a deadly shootout in Culiacán in which Sinaloa cartel gunmen forced the release of one of their leaders, Ovidio Guzmán López.