At least 10 people were killed in separate attacks in the northern Mexican state of Chihuahua overnight Tuesday, local authorities said.

Ciudad Juarez city police chief Juan Pablo Soria was killed in an attack Tuesday morning in a market where five civilians were also wounded in a shooting, said the authorities.

According to initial investigation, a heavily armed gunman arrived in a van with high-impact weapons and fired at a group of policemen, who then returned fire at Soria's order.

Local police also said four people -- three men and one woman -- were kidnapped and their bodies were found in the courtyard of an abandoned house south of Ciudad Juarez hours later, with signs of having been shot dead.

Meanwhile, two other murders were reported in different parts of Ciudad Juarez, which was considered as Mexico's most violent city.

Three other men were killed in different parts of Chihuahua.

More than 45,000 people have been killed in drug-related violence in Mexico since President Felipe Calderon launched a "war against organized crime" in 2006.