MANAGUA, Nicaragua — President Daniel Ortega's first formal talks with Nicaraguan opposition and civic groups since he returned to power in 2007 quickly became heated and confrontational Wednesday.

The dialogue, mediated by the Roman Catholic Church, came after more than 60 people died amid a government crackdown on demonstrations against social security cuts.

Ortega was greeted by jeers as he arrived at a seminary on the outskirts of Managua with his wife, Vice President Rosario Murillo, and a large security detail of about 500 riot police.

"Killers! Killers! Killers!" opponents chanted.

That animosity quickly appeared inside as well, when student representative Lesther Aleman interrupted Ortega, shouting that he must halt the repression to show he is serious about dialogue.

"Order it now, in this moment, the repression of the police, of the paramilitary forces, of your party's gangs that have been massacring and killing. ... In less than a month you've ruined the country; Somoza took years." Aleman said, alluding to dictator Anastasio Somoza, whose government was toppled by the Sandinista rebels in 1979. "You've done things we didn't even imagine you could do."

Ortega responded that the police were not repressing protests, but preventing chaos.

"You can't go around attacking police stations. Because it's not little angels out there — there are guns, too, shooting at police," he said.

Ortega shouted back at students that they had their own armed paramilitaries.

But Bishop Abelardo Mata of the Esteli diocese echoed the students' demand that the police return to their barracks, saying it was not an armed revolution.

Ortega warned that the protests are jeopardizing Nicaragua's economic stability.

"Today the Nicaragua that attracted investment is deeply wounded and I want to call on people to ease travel in the countryside, in the cities, to the free-trade zones," he said. "More than 160,000 workers are paralyzed and you're sending them to unemployment."

The dialogue includes university students who participated in the protests against the cuts, which Ortega later withdrew.

The students are now demanding greater democracy in a country where most governmental institutions are tightly controlled by Ortega's Sandinista party.

That demand — as well as justice for the dead protesters — has been taken up by business groups and others.

Other participants raised the possibility they may not continue in the talks.

Michael Healy, president of the Farmers and Producers of Nicaragua Union, who is representing the private sector in the talks, said Ortega's opening salvo suggested he was not really interested in resolving the crisis.

"This country is on the verge of chaos and it can't be that we have speeches tangled up in blaming the students and protesters for the massacres and deaths in the country," Healy said.

Ortega helped lead the revolution that overthrew Somoza, but was voted out of power in 1990. He returned in 2007, concentrated the power of the judicial and legislative branches and overturned term limits to perpetuate himself in power. Many now fear that Murillo, the main spokesperson for the government, wants to succeed Ortega in office.

"The dialogue is to demand justice for the victims and that Daniel Ortega leave power because he no longer has the capacity to run this country," Azalea Solis, a representative of the civic groups in the dialogue, told local media.

The meeting broke up with Ortega and his contingent walking out under shouts of "killers!" from students. Talks were scheduled to resume Friday, but it was not immediately known if Ortega would participate again.

A Guatemalan filmmaker was killed Wednesday night in the capital when protesters knocked down a huge metal decorative tree and it crushed him. Officials at Vivian Pellas hospital identified him as Eduardo Jessi Espigar Szejmer.