Police in Sri Lanka have arrested a bureaucrat attached to a parliamentary department for “aiding and abetting” Zahran Hashim, a suicide bomber allegedly responsible for one of multiple bomb attacks targeting churches and hotels across the country last month.

Hundreds of people, including foreigners, were killed and injured in the terrorist bombings, in some of the worst violence the island nation has seen in over a decade.

Mohamed Naushad Jalaldeen, a 42-year old transcripts department officer in the Sri Lankan parliament, was taken into police custody on Saturday based on information obtained from three other suspects who were arrested on Friday for alleged links with the banned National Thawheed Jamaath (NTJ). The NTJ is a local group that is widely believed to have carried out the Easter bombings on behalf of the Islamic State.

Jalaldeen’s arrest is the latest in a crackdown launched by police in the wake of the bombings. A school principal and a teacher were arrested on Friday for alleged links with the NTJ. Sri Lanka’s government and intelligence agencies have been criticized for their inability to prevent the attacks.