Lagos - Local police on Wednesday advised football fans to stay away from public venues showing World Cup matches after a bomb attack killed at least 21 in the north of the country.
"As a first choice, we are advising Nigerians to actually avoid these viewing centres as much as possible," national police spokesman Frank Mba told AFP from the capital Abuja.
Instead, Mba said the advice was to watch the tournament instead with family or friends.
A bomb, thought to have been hidden in a motorised rickshaw, exploded outside a viewing centre in the state capital of northeastern Yobe state, Damaturu, on Tuesday night.
At least 21 people were killed, according to a medical source, although state police put the death toll lower at 14.
Previous deadly attacks on big screen venues in Nigeria blamed on Boko Haram militants have prompted at least two states to close such centres on security grounds.
Mba said individual states were within their rights to order closures but police were working with centre operators and local agencies to improve security, particularly in the restive north.
Advice includes better searches of customers, increased vigilance from locals as well as creating pedestrian-only zones between 50 and 100 metres (yards) from venues to prevent car bomb attacks, he said.
"We're not calling for a total proscription. We would rather as a first choice sensitise and educate the public so they can take informed decisions," Mba added.