MEXICO CITY – Gunmen killed a navy rear admiral in Mexico on Friday, one of the highest-ranking officers killed in the country in a decade.

The Mexican navy said a rear admiral – who is just below the highest rank in the navy – was shot dead in the Pacific coast port city of Manzanillo. Local media gave his name as Fernando Guerrero Alcántar, but a navy spokesman would not confirm this or whether he was in uniform at the time.

The Navy said in a statement that he was driving his own private vehicle when the attack took place, so it was unclear whether the gunmen knew who he was.

He would be one of the most senior military officers killed in Mexico since 2013.

That year, gunmen from the neighboring state of Michoacan ambushed and killed Vice Admiral Carlos Miguel Salazar, the top naval commander in the neighboring Pacific coastal state of Jalisco. Members of the Knights Templar drug cartel were charged in that murder.

Vice admiral is a slightly higher rank than rear admiral.

Attacks by Mexican cartels on high-ranking officers have occurred, but are relatively rare.

However, the Mexican government has given more law enforcement responsibility to the militarized navy, army and National Guard in recent years, and they are now the frontline forces against the country’s drug cartels.

Manzanillo, because it is a port on the Pacific coast with direct shipments from China and other places in Asia, is highly valued by drug cartels trying to bring in chemical precursors to make the deadly opioid fentanyl.