A day before the 13th anniversary of Mumbai serial bomb blasts, a major terrorist strike in the city was averted on Saturday with the timely detection of two kilograms of explosive Ammonium Nitrate from the Byculla railway station in Central Mumbai.

The Anti-Terrorist Squad received an anonymous call around 10 am, saying that a suspicious object was lying in the men's toilet at platform number one of the station since the past few hours.

The bomb detection and disposal squad rushed to the station and took it immediately to Girgaum Chowpatty, where it was defused through a controlled explosion, police said.

Apart from the explosive filled in a polypack water bottle, police also recovered a pocket-size transformer, that could have provided necessary current if a detonator was to be attached to the explosive device, Police Commissioner A N Roy said told reporters in Mumbai.

Jaideep Singh, joint commissioner of police, ATS, said the explosive appeared to be a crude bomb, as it created a small crater in the sands on being defused. Samples of the explosive were collected and sent to forensic laboratory for examination, he said.

Roy said Ammonium Nitrate was also used in explosions that occurred at Varanasi earlier this week, but added that the explosive devices used there also contained RDX.

"The assembly, which we have seized, would not have caused a blast itself, since some vital components like detonators, energy source and a timer was missing," Roy said.

The police is not ruling out the possibility that terrorist elements may have left the explosive hidden there for a final assembly some time later, he said.

Police is taking the seizure seriously since it occurred a day before the 13th anniversary of Mumbai serial bomb blasts, which claimed 256 lives and caused colossal property damage.

Police across the city, particularly at places of worship and vital installations, were put on high alert following the recent twin blasts at Varanasi.

Random checks of vehicles, two-wheelers will be undertaken in the coming days, while public transport vehicles like buses and railways will be kept under surveillance to avoid any untoward incident.

Last month, three terrorists from Jammu and Kashmir [Images], allegedly having links with Laskhar-e-Tayiba, were arrested from the busy Nagpada area of South Mumbai, which is very close to the Byculla station.

Initial reports had indicated that they were part of the first module of a terrorist operation and were awaiting supply of explosives. The ATS has handed them over to the J&K police, as they were wanted for crimes registered against them in the valley.