By Miguel Gutierrez MEXICO CITY, June 27 (Reuters) - Mexico on Friday welcomed the U.S. Senate's approval of $400 million to fund equipment for its war on drug gangs and said it showed Washington finally recognized narcotics trafficking was a shared problem. The U.S. Senate approved $465 million in drug-fighting aid for Mexico and Central America on Thursday, delivering the first installment of the $1.4 billion in so-called "Merida Initiative" aid pledged by U.S. President George W. Bush during a visit to the Mexican city of Merida in 2007. The Mexico portion was $85 million less than Bush initially requested, but Mexican Interior Minister Juan Camilo Mourino praised U.S. lawmakers for softening conditions on the aid. "The terms under which the Merida Initiative resources were approved are respectful of the sovereignty and jurisdiction of both countries," Mourino told a news conference. "Aside from the resources in kind made available to our country, the importance of the Merida Initiative is that finally the United States is recognizing that the problem is shared, is bilateral, that this means it has a responsibility with this fight." Mexico, which is shelling out $7 billion for a 3-year military crackdown on the violent gangs that supply cocaine and other drugs to the lucrative U.S. market, has repeatedly asked the United States to focus on curbing the flow of illegal guns over its southern border. Mexico is grappling with a surge in violent cartel murders and estimates 97 percent of the arms used by its drug cartels are smuggled in from the United States. U.S. lawmakers initially wanted the Merida aid, which will include helicopters and surveillance devices, to be subject to monitoring, with a focus on protecting human rights. But the U.S. House of Representatives softened language in the bill after Mexico said attaching conditions would require legal changes that would violate its constitution. More than 1,600 people have been killed in drug violence this year as President Felipe Calderon's army offensive intensifies turf battles between rival cartels. On Friday, drug hitmen shot six police on patrol. And a regional police chief was murdered on Thursday as he ate lunch in Mexico City, the latest in a rash of police slayings. (Editing by Catherine Bremer and Stacey Joyce)
Police investigators arrive at a crime scene where a local police chief was found killed in Culiacan in the Mexican state of Sinaloa in this May 28, 2008 file photo. Breaking ...