President Maithripala Sirisena has issued a gazette notice banning three Islamic extremist organisations, including National Thowheeth Jama'ath that was blamed for the Easter bombings.
India has said that the onus is on Pakistan to create an environment free of terror and hostility.
Sri Lanka's new President Maithripala Sirisena on Monday unveiled his cabinet that included members from a cross-section of parties and announced fresh parliamentary polls in 100 days, two years ahead of schedule.
Violence erupted on Monday following which police imposed curfew in the Theldeniya area.
The National Tawheed Jamath is suspected of plotting the deadly Easter blasts.
Sirisena's sacking of Wickremesinghe was the culmination of an year of bitter relations between them on several policy matters. The president has been critical of the prime minister and his policies, especially on economy and security.
-- Seven suicide bombers believed to be members of an Islamist extremist group carried out the series of explosions. -- Police have so far arrested 24 people - mostly members of an Islamist extremist group - in connection with the blasts
As the island heads for elections, two major factors worry Sri Lankan President Mahinda Rajapaksa. One is the division in the Sinhala vote and the other is the prospect of the Tamils and Muslims voting heavily against him.
