"Terrorists may attack with little or no warning, targeting tourist locations, transportation hubs, markets/shopping malls, local government facilities, hotels, clubs, restaurants, places of worship, parks, major sporting and cultural events, educational institutions, airports, and other public areas." the state department said in a statement.

The state department urged the travelers to be aware of their surroundings while traveling to tourist locations and crowded public venues in Srilanka. 'Follow the instructions of local authorities and monitor local media for breaking events and adjust your plans based on new information', the statement read.

The travel advisory has come in the wake of recent dastardly attack in Sri lanka in which 290 persons were killed and more than 500 sustained injuries.

The department also urged its citizens to have a contingency plan for emergency situations and to follow the department of state on Facebook and twitter for any updates.

Earlier US condemned in its strongest terms the terror attacks in Sri Lanka on Easter morning. "Attacks on innocent people gathering in a place of worship or enjoying a holiday meal are affronts to the universal values and freedoms that we hold dear, and demonstrate yet again the brutal nature of radical terrorists whose sole aim is to threaten peace and security" the department said.

Terming these vile attacks as a stark reminder of why US remains resolved in fight to defeat terrorism, the department said that US embassy in Srilanka is working tirelessly to provide all possible assistance to its citizens affected by the attacks.

"We stand with the Sri Lankan government and people as they confront violent extremism and have offered our assistance as they work to bring the perpetrators to justice" the state department added.

The Indian High Commission has also issued helpline numbers for Indians stranded in Sri Lanka.