Authorities in El Salvador counted 635 homicides in May, making the month the single deadliest since the end of the Central American nation's civil war in 1992, the Associated Press reported.

Officials told the newswire the continued uptick in violence marks a deliberate attempt by criminal organizations to ramp up pressure on the government of President Salvador Sánchez Cerén, who has refused to negotiate with the country's powerful street gangs.

According to data made available by El Salvador's National Civil Police (PNC), 2,180 individuals have been murdered so far this year, EFE detailed; the statistics note 339 homicides in January; 308 in February; 481 in March; and 417 in April.

"This is the most violent month since 1992, and we know that there is even underreporting," José Miguel Fortín Magaña, the director of the Supreme Court's Institute for Legal Medicine, told the AP in an interview.

But Mauricio Ramírez Landaverde, who heads the PNC, said that criminals killed by rival gangs or by colleagues in the same criminal group accounted for 60 percent of the victims.

Pedro González, the leader of the PNC's anti-gang unit, told the Washington Post last month that nearly the entirety of El Salvador is split up between the Mara Salvatrucha and the 18th Street group, both descended from Salvadoran immigrant gangs in Los Angeles. The groups have diverse criminal interests, the policeman added.

The surge of violence is believed to be due to the collapse of a gang truce; both gang-on-gang violence and attacks on police and common citizens spiked after Sánchez, who took office in June, upped the ante by sending gang leaders to maximum-security prisons and encouraging police to use their weapons without fear in the line of duty or in defense of lives, according to the AP.

Former New York Mayor Rudy Giuliani earlier this month counseled El Salvador's leaders to forcefully go after the two groups in order to quell violence and restore order in the increasingly unstable Central American country.

"The biggest problem in New York was the mafia and then drug traffickers, but here it's two major gangs, and these two gangs need to be annihilated," Giuliani insisted, Reuters noted.