UNITED NATIONS, July 17 (Xinhua) -- United Nations Secretary-General Antonio Guterres has called on the Nicaraguan Government to end violence against demonstrators which has cost an estimated 280 lives.

Speaking in neighboring Costa Rica on Monday night, Guterres said that it was "an essential responsibility of the state to protect its citizens, and this basic principle cannot be forgotten, especially when, unfortunately, we have a death toll that is absolutely shocking," UN News said on its website on Tuesday.

The UN chief has called on the Nicaraguan Government to begin a national "political dialogue" to end the crisis which has gripped the country for nearly three months.

At least 12 people were killed over the weekend, mostly as police and paramilitary supporters of the government confronted demonstrators who have been protesting proposed reforms to the pension system across the country, since April 18.

Protesters are demanding that the long-serving president, Daniel Ortega, step down.

Guterres said that he was "not a supporter of simplistic analysis of complex problems, but there is one thing that is obvious: there is a death toll that is shocking due to the use of force on the part of entities linked to the state, that is not acceptable," said UN News.