Zeid Ra'ad al-Hussein, U.N. High Commissioner for Human Rights, addresses the Human Rights Council at the United Nations in Geneva, Switzerland February 26, 2018. REUTERS/Denis Balibouse

GENEVA (Reuters) - The United Nations human rights chief said on Wednesday that crimes against humanity may have been committed by state forces in Venezuela and voiced alarm at “the erosion of democratic institutions” in the Andean nation.

U.N. High Commissioner for Human Rights Zeid Ra’ad al-Hussein said his office had received credible reports of “hundreds of extra-judicial killings in recent years, both during protests and security operations”.

“I encourage the Council to consider mandating a Commission of Inquiry to investigate human rights violations in Venezuela,” Zeid told the U.N. Human Rights Council, holding its main annual four-week session through March 23.

Venezuela is among the 47 member states of the Geneva forum, where it enjoys support from allies led by Cuba, but it has been criticized by the United States and other Latin American countries for shrinking democracy and a food and health crisis.

Venezuela last week postponed its upcoming presidential vote to May 20 in a move cementing an opposition split as socialist incumbent Nicolas Maduro seeks re-election despite an economic crisis and global censure.

The main opposition coalition is boycotting the poll, saying it is a farce intended to legitimize a “dictatorship.”

The context for the presidential poll “does not in any way fulfill minimal conditions for free and credible elections”, Zeid said.

“I am deeply disturbed by the growing exodus of Venezuelans from their country, many of them in search of access to food and basic services,” he added.

A Reuters Special Report published last week followed a group of migrants as they fled Venezuela on a bus ride through five South American countries in a quest for a better life.