In an important development, the Anti-Terrorist Squad of Mumbai police has arrested three persons, two of them from Bihar, for their alleged complicity in the serial blasts on Mumbai's commuter trains on July 11 and seized 1.5 kg of gunpowder from them.

Kamal Ahmed Mohammed Vakil Ansari (32) and Khalid Aziz Raunak Aziz Sheikh (24) were arrested on Thursday from Basupati village in Bihar's Madhubani district while Mumtaz Ahmed Maqbool Ahmed Choudhary (38) was arrested from Turbe in Navi Mumbai Thursday night, ATS officials said.

Ansari and Sheikh were arrested at 2 pm on Thursday and flown to Mumbai, ATS officials said.

The three were produced before a Mumbai local court Friday afternoon, which remanded them to police custody for ten days, till July 30.

While initial reports suggested that they had been arrested under Maharashtra Control of Organised Crime Act, ATS officials told magistrate A V Shete that the trio had been arrested under the provisions of the Indian Penal Code, Indian Explosive Act, Explosive Substances Act and Indian Railways Act.

ATS officials told the court that they had searched the house of Ansari and seized 1.5 kg of black coloured gunpowder from his premises.

The officials also told the court that they had seized mobile phones from the accused.

These are the first arrests in the case, and ATS officials were hopeful of making a headway in the probe, sources said.

Home Minister R R Patil told the Assembly that three persons had been arrested, and the blasts probe was progressing at a 'rapid pace'.

ATS officials told the court that Ansari was not able to give a satisfactory answer as to why he possesed the gunpowder.

Preliminary investigations have revealed their complicity in the serial blasts, the officials said and asked the court to remand them to police custody for custodial interrogation.

Remanding the accused to police custody, the court observed that the charges leveled against the accused were of a serious nature and their custodial interrogation was necessary.

The trio has been charged under IPC Sections 302 (murder), 307 (attempt to murder), 324 (voluntarily causing hurt by dangerous weapons), 325 (causing grievous hurt), 326 (causing grievous hurt by dangerous weapons), 427 (mischief causing damage to property), 436 (mischief by fire or explosive substance with intention to destroy property) and 120-B (conspiracy).

The accused have also been charged under Sections 3,6, 9 (b) read with section 45 of the Explosive Substances Act.

They have been additionally charged with provisions of Indian Explosives Act.

The trio has also been charged under Section 151, 152, 153 and 154 of the Indian Railways Act.