Earlier in the day, Pope Francis said at the Vatican that he was "very worried" about the situation in Nicaragua and echoed the call of local bishops for an end to all violence.
The Pope said he was "very anxious about what is happening these days in Nicaragua", where citizens took to the streets beginning April 18 after the government announced changes to the nation's social security system. Dozens have been injured or arrested.
The measures would have increased income and payroll taxes, while reducing pensions by 5 percent.
The president criticized the demonstrators, comparing them with gangs that bleed the north of Central America and said that his only interlocutor to get out of the crisis was private enterprise. The protests began Wednesday in capital, when hundreds of critics of government came toger in a mall.
On Saturday, after four days of unrest, Mr Ortega addressed the nation for the fist time to call for negotiations.
Protesters accuse riot police and troops deployed across the country of carrying out most of the violence.
State-affiliated media showed images of armed soldiers patrolling the city center and said they were safeguarding strategic concerns after fires at several public buildings.
Analysts and business leaders said the protests were fuelled by dissatisfaction that went well beyond anger over pension reform. A police officer in Managua, the capital, shot in the head, was fighting for her life as other families arranged to bury their dead.
Marlin Sierra, director of human rights organisation CENIDH, said it had logged 25 deaths, mostly caused by firearms and rubber bullets. Nicabus, an worldwide bus line with links to Costa Rica and Honduras, said it has been forced to suspend services due to the violence.
Ortega has offered talks, but business leaders have rebuffed him, saying police violence must stop first.
Those remarks appeared to fan the flames, and soon afterward thousands of people spilled back into the streets in seven cities.
Nicaraguan media said Gahona, who was described as a journalist from the area, died from his injuries.
The center's director, Vilma Nunez, warned that there was "a lot of misinformation" going around that made obtaining the figure hard. Nicaragua has lseen since last Wednesday extraordinary popular demonstrations that have already become a real rebellion against the Ortega regime.
"We can no longer accept this government, we are protesting for the Ortega-Murillo couple to leave power", Ramirez said. "Here there have been dead, wounded, and he does not even apologise for his killings or the savage repression against the people", said Mauri Hernandez, one of thousands of demonstrators at a central rotunda.