Mexico City - Violent clashes left five police officers and four civilians dead in the north-western Mexican state of Sinaloa in the early hours of Tuesday, the police said.

The police officers were killed as they chased a group of armed men who had killed three young men on a street corner in the city of Culiacan, the authorities said.

The alleged killers barricaded themselves inside a house and fought police from there. Security forces finally entered the house and seized 10 AK-47 and 6 HK-G3 rifles, among other weapons.

The authorities did not say how many people they found inside the house or whether any of the alleged criminals died or were injured in the raid.

Another person died in a separate incident in Culiacan, after suffering a shot to the head.

On Monday, four police officers were found dead near Culiacan. They had been kidnapped on May 1, and their bodies showed signs of having been tortured.

Murders in Mexico have increased by 47 per cent in the first months of 2008, in comparison to a similar period in 2007, according to the country's public prosecutor's office.

According to Mexican authorities, 1,378 people were killed by organized crime in the country between January and May 22. (dpa)