Authorities in Dubai have reportedly detained five aides of Pakistan-based underworld don Dawood Ibrahim, sources said on Monday night.

These five are believed to be part of the list that was handed over to the United Arab Emirates authorities during the deportation of Aftab Ansari, main accused in the shooting incident at the American Centre at Kolkata in January last year, the sources said.

Although it is not immediately clear as to who the five are, reports reaching Delhi indicate that they could include Dawood's younger brother Noora, Mohammad Dossa and Aftab Bhatti.

There is no case pending against Noora, but he is believed to be instrumental in extortion activities and in handling investments made by the underworld don.

Both Dossa and Bhatti are accused in the 1993 Mumbai blast cases.

The police is awaiting confirmation from their Dubai counterparts on the reported detention, Joint Police Commissioner Javed Ahmed told PTI in Mumbai.

Relations between New Delhi and the UAE came under strain after the police there allowed another of Dawood's brother, Anees Ibrahim, safe passage to Pakistan in December last.

Mohammed Dossa, a smuggler, helped Dawood engineer the 1993 serial blasts in Mumbai by organising the landings of arms and ammunitions at Dighe coast in Raigad district.

The arms were sent from Pakistan to trigger explosions in Mumbai, Ahmed said.

Dossa, an absconding accused in the 1993 blast case, escaped to Dubai before the blasts in the metropolis on March 12, 1993. His moveable and immoveable properties have been attached by a special court in Mumbai.

Aftab Batti, a small-time criminal, fled to Dubai a few years ago and helped Dawood in his underworld operations.

He is allegedly instrumental in helping Dawood and Pakistan's ISI circulate fake currency in India and is facing cases under the Maharashtra Control of Organised Crime Act (MCOCA).

His brother has been arrested in Mumbai and is also facing charges of circulating fake currency in India.