A series of blasts tore through three churches and three luxury hotels in Sri Lanka, killing 253 people.

The external affairs ministry on Tuesday issued a fresh advisory asking citizens travelling to Sri Lanka to be careful and vigilant in view of last month's bombings in which over 250 people were killed.

In the advisory, the Ministry of External Affairs (MEA) said security situation in Sri Lanka is gradually returning to normal with the lifting of curfew and restrictions on social media and the opening of schools.

At the same time it said, "Indian nationals travelling to Sri Lanka are advised to be careful and vigilant."

It also asked Indian nationals requiring any assistance to get in touch round the clock with the Indian High Commission in Colombo and Assistant High Commission in Kandy as well as Consulates in Jaffna and Hambantota.

In the aftermath of the blasts last month, the MEA had asked citizens not to undertake non-essential travel to the island nation.

Nine suicide bombers carried out a series of devastating blasts that tore through three churches and three luxury hotels on the Easter Sunday, killing 253 people.