Colombo: Sri Lanka on Thursday released photographs of six suspects, including three women, wanted for their involvement in the deadly Easter attacks that killed nearly 360 people as police intensified search and arrested 16 people, taking the number of those under custody to 76.

Nine suicide bombers, believed to be the members of local Islamist extremist group called National Thowheed Jamath (NTJ), carried out a series of devastating blasts that tore through three churches and three luxury hotels on Easter Sunday.

Police Thursday night released the names and pictures of three men and three women and sought information regarding them from the public.

Earlier, officials said that with the arrest of 16 more people on Wednesday, the total number of suspects under police custody has risen to 76.

The arrested people were being interrogated at length by the investigation sleuths in connection with the bombings.

Many of the arrested people have suspected links to the NTJ, the group blamed for the bombings. However, the NTJ has not claimed responsibility for the attacks.

The Islamic State has claimed responsibility for the attacks and identified suicide bombers who carried out the devastating blasts.

Authorities have deployed thousands of troops to help police carry out search operations.

Over 5,000 army personnel have been deployed around the country.

"During the last 24 hours, there have been no major incidents. We have deployed over 6,300 troops. This includes 1,000 from the Airforce and 600 from the Navy," military spokesman Brigadier Sumith Atapattu said.

Meanwhile, a minor explosion happened behind the magistrate's court at Pugoda, the western province town, 40 Kms north of Colombo.

The police said that the explosion occurred in a garbage dump and that there were no injuries. A probe has been launched to ascertain the cause.

Search operations of suspected properties, arrests and detention of people and to place road blocks for such operations have been facilitated by the newly-enforced emergency regulations.

The regulations were adopted without a vote in Parliament on Wednesday.

The curfew will be imposed at 10 PM.

Malcolm Cardinal Ranjith, the head of the local catholic church, has asked all churches to stop masses until the situation improved, his office said.

On Wednesday, the Sri Lankan government admitted that "major" intelligence lapses led to the horrific coordinated attacks.