COLOMBO, Sri Lanka — Sri Lanka’s president on Tuesday called for the “immediate” lifting of a temporary ban on several social media networks, a clampdown that had been intended to prevent the spread of misinformation after devastating suicide bombings on Easter.
The restrictions, which were put into place quickly after attacks at three churches and three high-end hotels killed more than 250 people in Sri Lanka, reflected increasing global concern about the role that American-owned networks play in spreading hate speech and inciting communal violence.
The government’s statement on Tuesday called on the public “to use social media responsibly even though the ban is lifted, due to the prevailing situation in the country.” According to internet monitoring groups, Facebook, Instagram, WhatsApp and Viber were among those affected.
The decision to block networks was not new in Sri Lanka, which has a complicated history with social media. Last year, the government briefly restricted some platforms after rumors that spread largely on Facebook appeared to instigate a wave of anti-Muslim riots and lynchings.
But the government’s broad shutdown of social media immediately after the Easter attacks, which were tied to eight attackers linked to a local affiliate of the Islamic State, was unusual. Access was shut down before any social-media-inspired violence was known to have taken place.
It is unclear how effective the ban has been at curbing unrest, or whether information spread on social media has contributed to recent reports of some attacks on Sri Lanka’s Muslims and refugees from Pakistan and Afghanistan.
After the bombings, Muslims, who comprise about 10 percent of the country’s population, have reported mobs attacking their homes and storefronts and threatening violence. Some of the blocked media outlets were sporadically accessible. And many Sri Lankans have simply used V.P.N.s, or virtual private networks, to circumvent the restrictions.
For days, Sri Lanka’s capital, Colombo, had been on lockdown, with nightly curfews and army personnel deployed along largely empty roads. Recently, life has started slowly returning to normal around Sri Lanka, but security forces said that they are continuing to comb the country in “house-to-house searches” for people linked to the six attacks on churches and hotels.
The Islamic State, in a statement over the weekend, claimed responsibility for three additional suicide bombings that occurred Friday during a raid by security forces on a hide-out of National Thowheeth Jama’ath, its local affiliate, which is believed to have carried out the Easter attacks.
Despite the curfew being lifted in Colombo, security forces remained on high alert. The police have warned lawmakers that the group could still be planning further attacks, said a member of Parliament who sought to remain anonymous because of the sensitivity of the internal communication.
Three of the 15 people killed in Friday’s raid were identified as the father and two brothers of Zaharan Hashim, National Thowheeth Jama’ath’s leader, who was one of two suicide bombers to strike the Shangri-La Hotel on Easter, killing 33 people.
On Monday, in rare video and audio messages, Abu Bakr al-Baghdadi, the leader of the Islamic State, acknowledged that the attacks in Sri Lanka were carried out by fighters of his group.
Investigators in Sri Lanka have been trying to pin down direct connections between the attackers and the Islamic State hub in Syria. One lead they are following is possible travel to Syria by one of the Easter Sunday bombers.
Ruwan Gunasekara, a spokesman for the Sri Lankan police, said in a statement on Monday that 59 suspects “with terrorists links” have been detained since the attacks and investigators are questioning them. The authorities have also confiscated caches of weapons, explosives, “terrorist literature” and fake identification, Mr. Gunasekara said.