Mexican President Felipe Calderon has called for the United States to share responsibility in the battle against drug traffickers in the two countries.

墨西哥总统费利佩·卡尔德龙呼吁美国肩负起共同解决两国之间毒品走私问题的责任。

Crowds turned out to protest at the president's policies

His comments came on a one-day visit to the border city of Ciudad Juarez where three people connected to the US consulate¹（领事馆） were killed on Saturday.

Hundreds of demonstrators greeted Mr Calderon demanding the withdrawal² of Mexican troops from the town.

Meanwhile, Texas has increased border patrols in the wake of（随着……而来） the violence.

"The violence which has gripped Ciudad Juarez is connected to US drug consumption and the weapons which enter Mexico from the US," Mr Calderon was quoted as saying by Reuters.

Ciudad Juarez is at the centre of the battle between Mexican drug gangs over trafficking routes to the US. More than 2,600 people were murdered there in drug-related violence last year alone.

Lesley Enrique - a US citizen working at the Juarez consulate - her American husband, Arthur Redelf, and Jorge Alberto Sarcido - the Mexican husband of another consular³ employee - were shot dead in two separate incidents last weekend.

Both couples had just left a social event in the city when they were killed.

Enriquez, 35, and her 34-year-old husband were killed in a hail of bullets as they drove their car towards the US side of the border. Their one-year-old baby was found unharmed in the back seat.

In the second attack, gunmen opened fire on the car belonging to Jorge Alberto Sarcido, killing⁴ him and wounding his two children.

'Another planet'

Protestors frustrated⁵ with unrelenting（无情的，不松懈的） attacks of violence held up signs reading "government assassins" and accused President Calderon of living "on another planet", Reuters reported.

"Calderon has no idea what he is talking about", said activist⁶ Susana Molina.

The protesters have accused Mr Calderon's troops of provoking（挑拨，激怒） more violence between rival drug gangs by bringing in the army to try to crack down on（镇压，制裁） the problem.

The Governor of the US state of Texas, Rick Perry said he had increased police presence along the Texas border with Mexico.

"With the safety of Texans on the line, we can't afford to wait", Mr Perry was quoted as saying by AFP.

American federal agents are helping⁷ to investigate the most recent killings⁸.

Mexico is struggling to cope with a drug war that has killed some 18,000 people since 2006.