Sri Lanka stepped up security Wednesday as political parties staged low-key May Day commemorations after calling off scheduled rallies following fears of Islamist bomb attacks.
Officials said more police were deployed for cordon-and-search operations in many parts of the country, while the military also re-inforced road blocks and patrols.
Several roads in the capital were closed Wednesday as President Maithripala Sirisena and Prime Minister Ranil Wickremesinghe attended a tightly guarded public ceremony marking the 26th anniversary of president Ranasinghe Premadasa assassination.
Officials said police used extraordinary security measures for Sirisena's public appearance to commemorate Premadasa, who was killed by a suicide bomber during a May Day rally in 1993.
"His security used three identical convoys to bring the president to the commemoration," a police official at the function told AFP. "This was to make sure that no-one has advance warning about the vehicles used by the president."
Sirisena's Sri Lanka Freedom Party (SLFP) cancelled its May Day celebrations and instead was holding a closed-door meeting with senior stalwarts later in the day, officials said.
Former president and current leader of the opposition, Mahinda Rajapakse -- who leads a breakaway faction of the SLFP -- also cancelled his May Day event, and was attending a low-key meeting just outside Colombo.
The country has been under a state of emergency since Easter Sunday attacks killed 253 people at three churches and three luxury hotels.
The emergency gives sweeping powers to police and the military to arrest and detain suspects for long periods.
Police say they have arrested over 150 people suspected of links to jihadists who carried out the bombings.
Prime Minister Wickremesinghe said Tuesday that some suspects remained at large.
"A few more people involved in the attacks are out there and we hope to arrest them soon," Wickremesinghe said. "Even if we arrest all of them, the threat will not disappear."
He said Sri Lanka will have to work closely with international partners to neutralise the Islamic State, which claimed responsibility for the audacious bombings -- the worst single-day attack against civilians on the island.
Sri Lanka blamed the local National Thowheeth Jama'ath (NTJ) for the bombings. The group had pledged an oath of allegiance to IS leader Abu Bakr al-Baghdadi, who in a recent audio message praised the Sri Lanka attacks.
Schools were due to open on Monday, but authorities put it off by a week. The Roman Catholic church cancelled its Sunday services fearing a repeat of Easter bombings, but announced Tuesday that they will resume May 5.