MEXICO CITY, April 23 (Reuters) - Mexico has arrested a suspected leading hit man for the notorious drug-trafficking Gulf Cartel, officials said on Monday, in a boost for President Felipe Calderon's crackdown on traffickers.

Eleazar Medina was accused of working in the northeastern state of Nuevo Leon, just south of Texas. He was caught in the city of Nuevo Laredo, a Gulf Cartel stronghold which has been wracked by violence for three years. Federal police paraded him handcuffed before reporters with several alleged accomplices.

Officials did not say how many people Medina is accused of killing.

Calderon has sent troops across the country since taking office in December to crack down on drug cartels whose battle over routes and territory killed 2,000 people last year. The violence shows no signs of slowing.

"He was a major killer," said Fernando Castillo, a spokesman for the Attorney General's office.

Along with Medina and his alleged accomplices, police displayed an armory of drugs, communications equipment and weapons seized from the cartels in recent hauls, including three assault rifles painted gold.

The bulk of the killings in Mexico stem from a rivalry between the Gulf Cartel and an alliance of traffickers from the northwestern state of Sinaloa. The Gulf cartel suffered a major blow in January when Calderon extradited its captured leader Osiel Cardenas to the United States.

An opinion poll published in the daily Milenio on Monday showed 77 percent of those surveyed believed Calderon should push on with his crackdown on drug cartels, regardless of any extra violence it provoked.

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