Colombo: The bodies of 10 terrorists killed during a fierce gun battle with security forces in Sri Lanka's Eastern province last week were buried without any religious rites on Thursday afternoon, police said.

However, the bodies of six children killed in the same raid were buried as per the religious rites.

"Ten bodies were buried without conducting any religious activities on a request made by Muslim religious leaders," police spokesman Ruwan Gunasekera said.

They were buried following investigations and post-mortem, he said.

All Ceylon Jamiyyathuul Ulama or council of Muslim theologians had demanded "maximum punishment" for the perpetrators of the suicide attacks on churches and luxury hotels in the country that left at least 250 dead.

They had said that the suicide bombers should not be accorded religious rites at their funerals.

Six children and three women were among 16 people killed when militants linked to the deadly Easter Sunday bombings opened fire and blew themselves up during the fierce gun battle with security forces in Kalmunai city, about 360-km from Colombo, Friday night.

The shootout occurred as the security forces continued their hunt for members of the National Thowheed Jamaath (NTJ), the local terror outfit behind a series of devastating blasts that tore through three churches and three luxury hotels on the Easter Sunday.

According to police, most of those died during the raid were the close family members of NTJ leader Mohamed Zahran. His wife and a 4-year-old daughter survived the blast and are currently receiving hospital treatment.

The Islamic State claimed the attacks, but the government has blamed local Islamist extremist group NTJ for the attacks.

Sri Lanka has a population of 21 million which is a patchwork of ethnicities and religions, dominated by the Sinhalese Buddhist majority.

Muslims account for 10 per cent of the population and are the second-largest minority after Hindus. Around seven per cent of Sri Lankans are Christians.