Ryanair have cancelled all flights scheduled to take-off before 9am, leaving "lots of grumpy, bleary-eyed people" waiting, one passenger told ITV News.
More top news
Police are not linking the explosion of the "incendiary device" to others which have caused panic in the city.
An estimated 70,000 claimants transferred to Employment and Support Allowance (ESA) from other benefits since 2011 were underpaid.
Plastics is one of a number of environmental issues facing the world's seas, along with rising sea levels and warming oceans.