This article is more than 1 year old

This article is more than 1 year old

Sri Lanka’s president has said investigations into civil war-era human rights abuses weakened the country’s security apparatus and left it vulnerable to last Sunday’s suicide bomb attacks, as members of the government continued to try to diffuse blame for the attacks.

Maithripala Sirisena told Sri Lankan media outlets on Friday morning that there were up to 140 supporters of Islamic State in the country and that about 70 had been arrested.

“I will stamp out Isis from Sri Lanka,” he said. “Our police and security forces are capable of achieving this.”

Police said Mohamed Zahran Hashim, an extremist preacher who appeared in a video this week pledging allegiance to Islamic State, was among the attackers. They said he detonated his bomb in the Shangri-La hotel in Colombo on Sunday morning.

Sirisena said a “highly descriptive warning” about the impending attack was issued by a friendly nation – understood to be India – on 4 April, but he reiterated that he was never told about it.

“Neither the IGP [inspector general of police] nor the defence secretary informed me of the intelligence report,” he said. “I am not saying this to absolve myself from any responsibility. But this is the fact.”

In a sign of how the response to the attacks is already refracting through political divisions, Sirisena highlighted the role of investigations into intelligence officers, which he described as harassment and said were responsible for the “weakening of the armed forces”.

Sri Lankan defence and intelligence officials have been named as suspects in investigations into crimes such as the disappearance of 11 youths in September 2008 and the assassination of a journalist, Lasantha Wickrematunge, in January 2009.

Sirisena has frequently accused his political opponents in the government of being insufficiently supportive of the country’s security apparatus in the face of demands from UN human rights officials to conduct credible investigations into possible abuses committed during the country’s 26-year civil war against Tamil militants.

“Action will be taken against all officials who neglected their duties, and a total reorganisation the security establishment in the days to come will take place,” he said.

The defence secretary, Hemasiri Fernando, resigned on Thursday and the police chief is expected to quit soon.

Police said on an official Twitter account on Friday morning that Hashim, the leader of a local militant group, National Towheed Jamaat, known for his vitriolic extremist speeches on social media, died in one of the nine suicide bombings.

They also said they had arrested the group’s second-in-command, and that the assailants’ military training was believed to have been provided by someone they called “Army Mohideen”. Investigators had determined that weapons training had taken place overseas and at some locations in Sri Lanka’s Eastern province, police added.

They said the vehicles used in the attack were purchased from a car dealership in Kadawatha, a suburb of Colombo.

The operator of a copper factory who was arrested in connection with the bombings was suspected of helping Mohideen make improvised explosive devices and purchase empty cartridges sold by the Sri Lankan military as scrap copper, police said.

Muslim community leaders called for prayer gatherings to be held privately on Friday, both because of ongoing threats from Islamic extremists and in solidarity with the country’s Catholics, whose services are still suspended due to security fears.

Sufi mosques in particular have been warned of the threat from violent fundamentalists, who regard the sect as heretical, according to a police memo sent to Muslim organisations. At least 700 refugees from another sect, Ahmadis, are in hiding after fleeing their homes in the port city of Negombo.

In a predominantly Muslim area of Colombo’s Maligawatta neighbourhood, vegetable sellers laid their produce on the sidewalks near the mosques as women in long black chador shopped. Leaders at the neighbourhood mosques said they planned still to hold Friday noon prayers and both the police and volunteers would be guarding the neighbourhood to protect the faithful.

One prayer leader, Imtiyas Ahamed, said he planned to preach about how extremists such as Islamic State were not faithful Muslims. “In Islam it is not said to kill yourself and kill others,” Ahamed said.

As he spoke, men came into the mosque one at a time to pray. They sat on their knees and bowed toward Mecca, the sweat from their brows falling on the mosque’s purple and grey carpet.

Abdullah Mohammed, 48, was standing outside. “Everyone is nervous,” he said. “Not just the Muslims: Buddhists, Christians, Hindus – everybody’s nervous.”