They must shut by 2200 local time (2100 GMT) and public parks that admit children should close by 1800.
Two weeks ago, eight people were killed when the Islamist sect Boko Haram attacked the police HQ in Abuja.
On Sunday, its fighters bombed a beer garden in Maiduguri, killing 25.
This is the group’s most deadly attack to date – later on Sunday, it killed another 10 people with a car bombing in the city.
The group, which usually targets the north-eastern state of Borno, around Maiduguri, says it is fighting for Islamic rule, and campaigns against all political and social activity associated with the West.
Abuja city’s administration said it has also banned parking of vehicles on two roads where most government offices are located.
“These measures are necessitated by the need to ensure adequate security of lives and property in the federal capital territory [in light of] the prevailing security concerns,” the city’s spokesman said in a statement.
The BBC’s Naziru Mikailu in Abuja says beer gardens are busy after work at the weekends and the curfew is likely to prove unpopular.
After a lull, Boko Haram’s attacks have intensified in the last nine months.
In May, it staged attacks at the inauguration of President Goodluck Jonathan.
The group’s trademark has been the use of gunmen on motorbikes.
Dozens of people have been killed – mostly security officers and politicians but also a Christian preacher and Muslim clerics who have criticised Boko Haram.
The sect’s leader Mohammed Yusuf and several hundred of his supporters were killed by security forces in Maiduguri in 2009 after the group attacked police stations.