The shootings came ahead of a visit to the island by United Nations rights chief Navi Pillay later this month.
Pillay is due in Colombo on August 25 on a five-day visit in connection with allegations that Sri Lankan troops killed up to 40,000 civilians in the final stages of an ethnic war against Tamil rebels in 2009.
Sri Lanka has denied that its troops were responsible for killing civilians or committing any war crimes. In an unusually strongly worded statement, the Archbishop of Colombo condemned "unhesitatingly" the military shooting that killed three people and wounded over 50 others at a village just outside the capital last Thursday.
In a statement Cardinal Malcolm Ranjith accused Sri Lanka's army of violating the sanctity of St. Anthony's church, beating up people who rushed there to escape the army shooting.
"We wish to condemn unhesitatingly the attack that was carried out by some elements of the (armed) forces on people who had sought refuge at St. Anthony's church," the ar