By Lorne Matalon

MEXICO CITY (Reuters) - Mexico's lower house of congress has approved a bill that will require the federal government to provide financial support to victims of the country's brutal gang violence.

The lower house said congress unanimously backed the bill, known as the General Victims Act, which will provide financial, legal and medical aid to Mexicans caught up in the turf wars between drug gangs and their clashes with security forces.

More than 50,000 people have died in drug-related violence since President Felipe Calderon sent in the army to crush the cartels soon after taking office in December 2006.

Thousands of people have also gone missing during that period and victim rights groups have complained of abuses by government security forces.

According to the bill, which was passed last week by the Mexican senate, victims of criminal violence will be eligible for support payments of up to 950,000 pesos ($73,000). Calderon is expected to sign the bill into law within 60 days.

Rampant lawlessness is one of voters' main concerns as they prepare to elect Calderon's successor on July 1. Calderon cannot legally run for reelection.

The president's conservative National Action Party is trailing way behind the opposition Institutional Revolutionary Party, or PRI, which ruled Mexico for most of the past century.

The bill will also direct the federal government to search actively for missing persons, make public apologies where warranted, and build shelters for people at risk from violence.

PRI Congressman Arturo Zamora told Reuters the bill was a major step forward for Mexico.

"For the first time, federal, state and local governments will be legally bound to work together to create a special office to look into the issue of people at risk," he said.

"This initiative will also create a database of missing people, those who have been killed and those who say they've been forced to move to another part of the country because they feel they are under threat," he added.

Mexico's office of the United Nations High Commissioner for Human Rights said the law will help address the "precarious situation" faced by victims of violence and rights violations.

Citing the recent killing of Mexican journalist Regina Martinez in the coastal state of Veracruz, the U.N. said there were still serious crimes in need of investigation.

(Reporting by Lorne Matalon; Editing by Sandra Maler)