Authorities in the Mexican state of Michoacan have arrested 28 police officers who make up the entire police force of the central town of Ocampo, to be questioned in connection wtih the killing of a politician, media reported on Sunday.

State officials said the police officers were taken in by the internal affairs department and questioned "in the event anyone has taken part in acts that violate the town's codes." However, they did not provide details on any suspected link between the police and last week's murder of mayoral candidate Fernando Angeles Juarez.

Ocampo, with a population of some 24,000 people, is a rural township located 95 miles (150 kilometers) west of Mexico City. Last Thursday, the center-left politician was gunned down while preparing his campaign, as Mexico gears up for a general election scheduled for July 1.

Read more: Top drug cartel leaders killed in Mexico near US border

The run-up to the election has been marred by gang violence, making the 2018 election campaign the bloodiest in Mexico's modern history. At least 18 election candidates for various posts have been killed so far. In addition to Juarez, the causalities include another mayoral candidate in Michoacan, Omar Gomez Lucatero, who was running in the gang-dominated township of Aguililla.

'Evolution' of drug gangs

Mexican security analyst Alejandro Hope said the spike in violence was partly caused by the country's drug cartels branching out into other kinds of crime. In addition to narcotics, the gangs are now involved with extortion, fuel theft, and even extorting money from local governments by forcing them to sign inflated public contracts. Segments of the police force are also believed to be highly corrupt and committing kidnappings and murders at the cartels' behest. 

"With the evolution of crime, it becomes much more important to gain control over territory, over local governments," Hope told the AP news agency.

The gangs attempt to expand their influence inside the police and among public officials, leading them to eliminate hostile politicians, he added.

Mexico's federal government has been struggling to suppress the nation's drug cartels. Despite repeated crackdowns, official numbers registered year as the most violent in the last two decades, with 25,339 homicides.

dj/msh (AFP, Reuters)