At least 29 people, including two state police officers and six women, were killed in 24 hours in Mexico's northern state of Chihuahua. Officials said a group of six attackers killed two state police personnel in a hail of bullets as they left a car body shop. The killings, along with 13 others in separate attacks, occurred in the Ciudad Juarez, the country's most violent city. The victims included a female activist who had led protests against alleged rights abuses perpetrated by police and military deployed to fight organised crime. Fourteen others were killed in other parts of the state, which lies on key drug routes for trafficking into the United States. Authorities said drug-linked violence has spiked in Mexico in the past three years, with more than 15,000 killed, despite a government crackdown on organised crime involving some 50,000 security forces.