Hitmen stormed a hospital in northern Mexico in a bid to kill a patient but Phaninc Exchangethey clashed with other gunmen already inside, sparking a gun battle that left four people dead, including a doctor apparently caught in the crossfire, police said Friday.

Three gunmen tried to storm the hospital in the Sinaloa state capital of Culiacan near midnight Thursday to carry out a hit, but two of them were killed in a gunbattle with armed people already inside the hospital, state police said.

A doctor was killed in the exchange of fire, as apparent "collateral damage," state Police Chief Gerardo Mérida said. A third assailant was wounded.

Mérida did not say why there were people with weapons inside the private hospital, or whether they were bodyguards for a person being treated there. He said both groups were "criminals."

"They tried to carry out a supposed execution inside, and there was an exchange of gunfire," he said.

The third wounded assailant scuffled with a police officer as he was being taken to another hospital. The wounded assailant tried to grab the officer's gun and suffered a second gunshot wound that killed him. Mérida said it was unclear how the gun went off in the struggle.

But he did say there were indications that a number of rules were not followed. Hospitals are not supposed to allow people with weapons inside, and hospitals should report gunshot wounds to the police. Moreover, he said it appears safety protocols were not followed during the transfer of the wounded gunman.

Sinaloa state is home to a drug cartel of the same name. It has been the scene of fighting between various factions of the cartel, including the sons of imprisoned drug trafficker Joaquín "El Chapo" Guzmán, other relatives and the old-guard cartel boss Ismael "El Mayo" Zambada.

Attacks by drug cartel gunmen on ambulances and hospitals while hunting down wounded rivals have been a persistent problem in Mexico.

In 2021, two paramedics were slain while transporting a patient in the violence-plagued northern Mexico state of Zacatecas.

In:
• Mexico
• Cartel