In a press release, the police yesterday said the "rocket projectiles" have likeness to explosives.

The press release said legal steps will be taken after having explosives experts' opinion on the recovered materials.

The arrested are Rezaul Karim, Nur Alam alias Badal and Sayed Kamruzzaman alias Kamrul alias Tanu.

Acting on a tip-off, a special police team raided the office of Trans Air Express courier service on the first floor of a building at Arambagh at 10:00pm and made the recovery.

The team also recovered two sewing machines, a pump, four passports and seals of various companies from the place.