An explosion rocked a shopping mall in Nigeria's capital, Abuja, killing at least 21 people, according to Reuters.

The blast, blamed on Islamic extremists, came as Nigerians were preparing to watch their country's Super Eagles play Argentina at the World Cup in Brazil, Reuters reported.

Many shops at the mall have TV screens, but it was unclear if the explosion was timed to coincide with the match, which started an hour later, according to Reuters.

Soldiers shot and killed one suspect as he tried to escape on a power bike and police detained a second suspect, Mike Omeri, the government spokesman for the insurgency, said in a statement, Reuters reported. Omeri urged people to be calm and said the government was doing everything possible "to check the activities of insurgents."

Police Superintendent Frank Mba said 17 people were wounded and 21 bodies were recovered, according to Reuters.

It is the latest in a series of violent attacks blamed on Islamic extremists, making Nigerian security forces appear incapable of curtailing the near-daily attacks concentrated in the northeast, where Boko Haram extremists have their stronghold, Reuters reported.

Abuja is in the center of Nigeria and the militants have spread their attacks to the capital, according to Reuters. Two separate explosions in Abuja in April killed more than 120 people and wounded about 200 at a busy bus station. Both were claimed by Boko Haram, which has threatened further attacks.

Nigeria's military and government claim to be winning the war in the 5-year-old insurgency against Boko Haram, but the tempo and deadliness of attacks has increased this year, killing more than 2,000 people so far compared to an estimated 3,600 killed over the past four years, Reuters reported.

Omeri, the government spokesman, said security agencies are "handling the situation" at Wednesday's bombing, according to Reuters. He said that "every step is being taken by the government to check the activities of insurgents in the country and advised Nigerians to remain vigilant and conscious of movement of unidentified people."