Nigeria's coach Stephen Keshi watches the 2014 World Cup Group F soccer match between Argentina and Nigeria at the Beira Rio stadium in Porto Alegre June 25, 2014. [Photo/Agencies]

PORTO ALGRE, Brazil - Nigeria coach Stephen Keshi says he is saddened by the deadly explosion at an Abuja shopping mall shortly before his team played Wednesday at the World Cup, and that his team's progression to the second round is unlikely to offer any solace to the country as it suffers terrorist attacks.

"How much of a victory is football going to give for those lives?" he said.

Last week, a bomb struck a World Cup viewing site in Nigeria, killing 14.

Wednesday's explosion was blamed on Islamic extremists but it was unclear if it was timed to coincide with the match.

"What are they doing these guys? They did it the first game, and now they did it again. It is sad," said Keshi, who was unaware of the second incident when asked about it immediately after the match.

Nigeria became the first African nation to reach the knockout stages in Brazil despite losing 3-2 against Argentina. It earlier drew against Iran and beat Bosnia-Herzegovina, earning second place in Group F.

Nigeria has been battling a brutal Islamist insurgence led by the Boko Haram group for around five years. The group gained international notoriety in April for the mass abductions of more than 200 schoolgirls, and is blamed for this week's abductions of another 91 people.

Around 1,000 Nigerians made the trip to Brazil's southern city of Porto Alegre to support the national team.

Some wore t-shirts emblazoned with the slogan "Soccer against Boko Haram."

"We need God's intervention to stop this from happening. I don't think these people are humans. They are hiding behind masks," said one supporter, Kenneth Okechu-Kwu Onfemere.

He said that he hoped football could bring some joy to the country.

"Football can bring love, happiness and unity. It can make us forget our problems."