CAIRO (AP) — The United Nations' human rights chief is criticizing a "pervasive climate of intimidation" in Egypt ahead of the presidential election in which President Abdel-Fattah el-Sissi faces no serious challenge.

El-Sissi is virtually certain to win re-election in the March 26-28 vote after a string of would-be contenders withdrew under pressure or were arrested. The sole challenger is an obscure politician who is also one of the president's most ardent supporters.

Zeid Ra'ad al-Hussein says Wednesday in an annual report submitted to the U.N. Human Rights Council that presidential hopefuls "have allegedly been pressured to withdraw, some through arrests."

He also says "independent media have been silenced, with over 400 media and NGO websites completely blocked."

Egyptian authorities have intensified their crackdown on local and foreign media ahead of the election.