National Security Advisor Ajit Doval and top intelligence chiefs of the country on Monday visited the blast site in West Bengal's Burdwan and assessed the progress of investigations.
NIA director general Sharad Kumar, NSG director general Jayanta Narayan Chowdhury and Intelligence Bureau director Syed Asif Ibrahim accompanied him during the over 30 minute visit to the house at Khagragarh where the blast took place on October 2, police said.
Doval and the three top officials visited the room where the blast occurred, during which two suspected terrorists were also killed.
They also went to the room which had served as the laboratory of the suspected terrorists and climbed the roof top of the house to check the visibility of surrounding areas.
Doval also inquired where the two children of the suspected terrorists stayed in the house.
The children, who are toddlers have since been taken into custody along with their mothers, one of whom is the widow of one of the suspected terrorists who died in the explosion.
Later, Doval met the district officials and asked about the progress of inquiry into the blast, the police added.
The four top officials then left for Kolkata to meet Chief Minister Mamata Banerjee at the state secretariat 'Nabanna'.
Earlier, the security and intelligence chiefs flew in to Burdwan by a chopper from NSC Bose International Airport. They had reached Kolkata in a IAF special aircraft this morning.
The present visit was the second in four days by the NIA director. Kumar after his first visit to Burdwan and Murshidabad on
Friday had said that the arrested persons in connection with the blast and their associates were members of Jamaat-ul-Mujahideen Bangladesh and were making IEDs to be transported to the neighbouring country for possible terror attacks.
The visits by top security and intelligence chiefs come ahead of the union government's move to send a report to Bangladesh following a request from that country.
Three persons, including the two women were arrested in connection with the blast and were interrogated by the NIA.
The PMO is giving utmost importance to the terror issue in Bengal after the Burdwan blast and subsequent revelations of a well-oiled terror network using madrasas.
On the other hand, the Trinamool-led government came under heavy fire from the opposition for trying to keep the NIA at bay after the Burdwan blasts. It was CID, which was entrusted with the investigation, until NIA suo moto took up the case.