Troops have been deployed to Nigeria's main airports in a security clampdown ahead of a major international economic conference next week in Abuja after two bomb blasts left scores dead in the capital.
Armed troops have been stationed at the departure and arrival gates of both Abuja's international airport and that of the economic capital Lagos, sources say.
In Lagos, cars may no longer drop passengers off outside the airport terminal but in front of a church some 200 metres where they must take a shuttle.
The measures are in addition to precautions announced earlier ahead of the three-day World Economic Forum on Africa, dubbed the "African Davos", beginning on Wednesday, which Chinese Premier Li Keqiang is due to attend.
Two deadly car bomb attacks some two and a half weeks apart in an Abuja suburb blamed on the Islamist sect Boko Haram sparked the security concerns over the WEF, described as the most prestigious international event to come to Abuja.
April 14 in Abuja's Nyanya suburb saw the capital's deadliest attack ever, when 75 people were killed, and the second was a stone's throw away, considered a "copy-cat" attack and claiming 19 lives on Thursday.
Also on April 14, suspected Boko Haram gunmen kidnapped scores of schoolgirls in northeastern Nigeria, the main theatre of their insurgency that has killed thousands since 2009.
The US consulate in Lagos warned in an advisory on Friday that "groups associated with terrorism" could be planning to attack a luxury hotel in Lagos.
The WEF said in a statement that its security arrangements for the conference, to be held at a top Abuja hotel, were "robust".
"There are no plans to make any changes to the programme or content of the meeting," it said, offering sympathy for the victims of the attacks.
Nigeria, however, announced that all government offices and schools would be shut during the conference, while local organisers have said more than 6000 police and soldiers would be deployed to ensure delegates' safety.
