* Pillay says has received reports of "excessive force"
* Mexican teen shot dead recently when patrol fired across border
* Shootings occur on smuggling routes
By Stephanie Nebehay
GENEVA, Oct 18 (Reuters) - The United States has used excessive force against immigrants along the Mexican border and should cooperate in investigating border killings, including those of many young people, the top United Nations human rights official said on Thursday.
"There have been very many young people, teenagers, who have been killed at the border," Navi Pillay, the U.N. High Commissioner for Human Rights, told a news conference.
"The reports reaching me are that there has been excessive use of force by the U.S. border patrols while they are enforcing the immigration laws," she added.
The family of a Mexican teen shot dead when the U.S. Border Patrol opened fire on a group of rock throwers in Mexico last week is planning to bring a lawsuit alleging excessive use of force, Mexican authorities said on Monday.
The Border Patrol said an agent in Nogales, Arizona, opened fire across the border into Mexico on Oct 10. Mexican authorities said 16-year-old Jose Antonio Elena Rodriguez was shot dead in the incident.
He was shot seven times in the back in the incident that began shortly before midnight when Border Patrol agents responded to reports of two suspected smugglers in Nogales and watched as they dropped drugs on the Arizona side of the border.
Arizona straddles a major route for Mexican smuggling networks hauling drugs and illegal immigrants to the United States, and running guns and cash profits back south to Mexico.
The Elena Rodriguez shooting came more than a week after a Border Patrol agent was shot dead near the border in an apparent friendly-fire incident.
The latest shooting brought sharp criticism from Mexico's foreign ministry, which said that the initial report on Elena Rodriguez "creates serious, new doubts about the use of lethal force by U.S. Border Patrol agents, something that both the Mexican government and society strongly deplore and condemn".
Pillay said that she agreed with remarks by Mexico's foreign ministry that the disproportionate use of lethal force during immigration controls is "unacceptable under any circumstances".
"So I would urge the U.S. and Mexico to redouble their efforts to investigate promptly and transparently these incidents," she said.
U.S. President Barack Obama's administration is working closely with that of Mexican President Felipe Calderon to curb smuggling over the porous, nearly 2,000-mile (3,200-km) border. A drug war has killed about 60,000 people in Mexico during Calderon's term.
Pillay said that under international human rights standards, law enforcement officials should use non-violent means before resorting to the use of force and firearms.
Victims of unlawful violence, or their families, should have access to the courts and justice, Pillay added.
Pillay, during an official visit to Mexico in July 2011, voiced concern at deteriorating conditions for migrants there, who originate mainly from Central American countries. (Reporting by Stephanie Nebehay; Editing by Michael Roddy)