The CBI on Friday recovered arms, including foreign-made revolvers, and crude bombs along with several identity documents of Trinamool leader Sheikh Shahjahan from the house of one of his aides in Sandeshkhali.

The arms recovery — while the second phase of the general election was under way — created a political storm with some BJP leaders demanding the arrest of chief minister Mamata Banerjee.

"The Central Bureau of Investigation (CBI) has today recovered large number of arms and ammunitions including foreign-made pistol and revolvers, during searches conducted at two premises in Sandeshkhali... in a case related to violence against Enforcement Directorate (ED) officials,” a CBI statement said.

A source said there was specific information about arms and explosives in the house, which had been under lock and key for some time.

"The cache was hidden under the floor; the floor had to be dug,” a CBI officer said. "Some of the arms were licensed in his (Shahjahan's) name."

The seizures were made from the home of Shahjahan’s aide Abu Taleb Sheikh, officers said. The other house raided, also in Sarberia village, was that of Shahjahan.

Some local people said Abu, who has several businesses, had close ties with the local Trinamool. "He was seen in the area even a couple of days ago," a villager said.

An ED team that had come to raid Shahjahan’s home in Sandeshkhali, North 24-Parganas, on January 5 in connection with alleged PDS irregularities had faced a mob attack.

Shahjahan and several aides were arrested after villagers demonstrated for days in February, accusing them of land-grab and sexual assault. Calcutta High Court later handed over all these cases to the CBI.

The CBI said the seizures included three foreign-made revolvers, an Indian revolver, a Colt (an official police revolver), a foreign-made pistol, a country-made pistol, "120 pieces of 9mm bullets, 50 pieces of 0.45-calibre cartridges, 120 pieces of 9mm calibre cartridges, 50 pieces of 0.380 cartridges and eight pieces of 0.32 cartridges".

A source said it was being probed how a police revolver came to be part of the cache.

Realising that bombs too had been stored in the house, the CBI team took the help of the National Security Guard, an elite anti-terror force. The NSG commandos used a specialised robot to extract the crude bombs and take them away for disposal.

The seizures include bills from a licensed arms dealer and ID documents of Shahjahan, including his Aadhaar and voter I-card, sources said.

"We are probing if the bills are real and if these government ID documents were used for the procurement of arms and ammunition from the licensed dealer," a CBI source said.

He added: "During investigations, information was received that items lost by the ED team (such as mobiles and laptops) and other incriminating articles may be hidden at the residence of an associate of Shahjahan Sheikh at Sandeshkhali…. Accordingly, a CBI team along with CRPF personnel searched two premises."

Suvendu Adhikari, leader of the Opposition in Bengal, demanded that Mamata be arrested and Trinamool declared a terror outfit.

Trinamool spokesperson Kunal Ghosh said: “The entire matter looks staged.”

Sandeshkhali, which falls under Basirhat constituency, votes on June 1.