Colombo: Sri Lanka police on Tuesday arrested their top commander and a former defence chief over their alleged failure to act on advance warnings of the deadly Easter Sunday attacks which claimed over 250 lives.

According to an AFP report, Inspector-General Pujith Jayasundara and former defence secretary Hemasiri Fernando were undergoing treatment when detectives had come to arrest them. The arrest was made on the instructions of Attorney General Dappula de Livera.

The Attorney said in a letter to the acting Police Chief that the arrested officials should be brought before a magistrate for their “criminal negligence”.

“Their negligence amounts to what is known under international law to be grave crimes against humanity,” AFP quoted his statement.

The report also said that apart from the arrested officials, the attorney-general has named nine senior cops who were involved in the security lapse.

Sri Lanka has been on the edge since the April 21 horror when suicide bombers exploded themselves in three churches and three luxury hotels besides two other places. Most targets were in Colombo. The killings were the worst to hit Sri Lanka since the end of the civil war a decade earlier. The unrest was triggered on Sunday after a group of people stormed into Chilaw town following the Facebook post by a Muslim shopkeeper about “an attack plan”.

Sri Lankan authorities say most of the 150 people suspected to have been linked to the last month’s attacks have died or been arrested but many still fear that the government has not caught all potential militants.