Sri Lankan police on Sunday reported there had been a seventh explosion, a few kilometres south of capital Colombo.
This comes after six explosions ripped through three churches and luxury hotels on Sunday, killing nearly 140 people.
Police say the latest explosion was at a hotel near the national zoo in Colombo.

Landslide at Guinea landfill kills 30, government says
New Zealand to introduce bill banning social media for children under 16
Drone attack kills 2 children, burns logistics hub in Russia's Krasnodar
Offices, schools closed in southern Taiwan due to torrential rain
Israeli airstrikes in Gaza kill 2 people, injure 7