Soldiers stood guard as the Catholic Church in Sri Lanka held its first regular Sunday mass since the suicide bombings on Easter Sunday which killed more than 250 people.
As services took place, troops and armed police patrolled the streets leading to churches and stood outside compounds with worshippers, who were required to produce identity cards and face body searches before entering.
Church volunteers had to identify known parishioners - who were told to bring minimal baggage - and point out anyone they felt was suspicious.
Officials also banned parking near the buildings.
The heightened security comes after seven suicide bombers targeted two Catholic churches and a Protestant church, as well as three luxury hotels on the island last month.
Sunday services were cancelled in the weekends following the bombings as it was feared more attacks could take place.
Instead, worshippers heard mass through a live TV transmission from the home of Archbishop Malcolm Ranjith.
Church-run schools could now also reopen on Tuesday if officials are satisfied with security measures in place.
According to President Maithripala Sirisena, "99%" of the remaining suspects linked to the bombings have been arrested and their explosives have been seized.
He said it is safe for tourists to return to Sri Lanka.
Islamic State has said it was behind the attacks, which were carried out by local radicalised Muslim groups.
Police said the National Towheed Jamaat and Jammiyathul Millathu Ibrahim groups planned the attacks.
Zahran Hashim, a preacher from eastern Sri Lanka, may have led the attackers and was one of the suicide bombers, according to officials.
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