Nigeria’s election commission has postponed presidential and parliamentary elections by one week, just hours before the polls were to open.

The chairman of Nigeria’s Independent National Electoral Commission (INEC), Mahmood Yakubu, told reporters Saturday morning — about five hours before polls were supposed to open — that “this was a difficult decision to take but necessary” for successful elections to take place.

He gave few details about why the change was made, but said “proceeding with the election as scheduled is no longer feasible.”

Local media had reported that voting materials had not been delivered to all parts of the country.

An official of the election commission told Reuters news agency that “some result sheets and some ballot papers are reportedly missing.”

Nigeria's President Muhammadu Buhari greets his supporters during a campa
Nigeria’s President Muhammadu Buhari greets his supporters during a campaign rally ahead of the country’s presidential election in Rivers State, Nigeria, Feb. 12, 2019.

Close race expected

The election is expected to be a tight race between incumbent President Muhammadu Buhari and his main challenger, former Vice President Atiku Abubakar.

Nigerian authorities increased security across much of the country Friday ahead of the elections.

Officials in Nigeria’s Kaduna state Friday reported at least 66 deaths in a wave of violence. State officials said the victims included 22 children.

Kaduna is an area known for its ethnic tensions, Christian-Muslim violence and election-related unrest.

Hundreds of people were killed in the region in 2011 when then-opposition candidate Buhari, a Muslim former military ruler from the north, lost to Goodluck Jonathan, a Christian from the south.

FILE - Nigeria's main opposition party presidential candidate Atiku Abuba
FILE – Nigeria’s main opposition party presidential candidate Atiku Abubakar speaks during an interview with Reuters in Lagos, Nigeria, Jan. 16, 2019.

President Buhari, 76, who beat Jonathan in a rematch in 2015, is running for re-election against main challenger Abubakar, a 72-year-old businessman and former vice president.

Along with ongoing violence in Kaduna, Nigeria is dealing with the decadelong Boko Haram Islamist insurgency in the northeast, and banditry and kidnappings in the northwest.

Before the announcement of a postponement, U.S. Secretary of State Mike Pompeo spoke with both President Buhari and Abubakar by phone on Friday, and “underscored U.S. support for the Nigerian goal of free, fair, transparent and peaceful elections.”

Pompeo welcomed both candidates’ pledges to accept the results of a credible election process and said the United States wants to see elections that reflect the will of the Nigerian people, according to a State Department statement.

Pompeo noted the “deep and long-standing partnership” between the United States and Nigeria, Africa’s most-populous democracy and the continent’s largest economy.