Tuesday, 23 April is the national day of mourning in Sri Lanka after a wave of suicide bombs that hit three churches and three luxury hotels left more than 300 dead and 500 injured on Easter Day. At least 36 out of those who died in the attacks were foreigners, including at least 10 Indians.

It's been two days since the attack and there hasn't been much headway except for a few speculations and suspects behind the attacks and in today’s Big Story Podcast we look what we know about the Sri Lankan attacks so far and what we don’t.

A Sri Lankan minister said that the attack was carried out in retaliation to the attack on Muslims in Christchurch on 23 April. Later into the day ISIS claimed the attack. A few questions arise:

* First, how much presence does the ISIS have in South Asia to be able to carry out this attack?

* Second, if it is a response to the attack in New Zealand that happened barely a month back – is a month enough time to plan and coordinate a large scale attack involving suicide bombers?

* Third, What is this super obscure group called the National Thowheeth Jamaath that has been blamed for the attack?

* Fourth, What has been the relationship between the Muslim and Christian populations in Sri Lanka — is there any history of enmity?

For all these questions, tune in to The Big Story podcast