Nine suicide bombers, including a woman had carried out the deadly explosions.

Sri Lankan Police said Friday they have arrested a school principal and a teacher for their alleged links to the local Islamist extremist group National Thawheed Jamaath (NTJ) blamed by the government for the deadly Easter Sunday bombings which killed nearly 260 people.

The 56-year-old principal and the 47-year-old teacher at a school in Ataweerawewa were arrested from Horowpathana city on Thursday, police said.

The Special Task Force in Horowpathana made the arrests, they said.

The suspects have been identified as Noor Mohamed Addu Ul and Ajibul Jabar, residents of Kapugollewa, Horowpathana, Colombo Page reported.

The police have received information that they have had direct ties with the NTJ and the leader Mohamad Sahran Hashim, who carried out the suicide attack on Shangri-La Hotel in Colombo on April 21, it said.

The suspects will be produced before the Kebithigollewa Magistrate court Friday, it added.

Nine suicide bombers, including a woman, carried out a series of devastating blasts that tore through three churches and three luxury hotels, killing 258 people and injuring over 500 others on the Easter Sunday.

The Islamic State claimed responsibility for the attack, but the government has blamed the NTJ for the bombings.

Widespread communal riots have followed the Easter blasts in Sri Lanka. Anti-Muslim riots have killed one person and caused extensive damage to homes, businesses and mosques in Sri Lanka this week.

The Sri Lankan police have said over 70 people have been arrested for attacking the Muslims.