That call turned out to be fortuitous for the police.
The loud ringing startled two men in the next stall, busy assembling bombs that they were planning to set off ahead of Narendra Modi’s ‘Hunkar rally’ in the city’s Gandhi Maidan, not far from the railway station.
Flustered by the sound, the men dropped the bomb in the cistern of the toilet, and it exploded, moments before Mr Modi, the BJP’s presumptive prime minister, arrived in the city.
One of the alleged bombers, Ainul alias Tarique, was injured. His associate Imtiaz Ansari tried to run away, leaving some of the material and carrying with him a bag of explosives.
But Ansari was caught by policemen patrolling the railway station. He has now been named as the mastermind of the serial blasts that killed six people and injured over 80.
Three people have been arrested till now.
A third suspect, Tabish alias Ansari, was picked up from Motihari yesterday, after the police found that he had been in constant touch with Imtiaz.
The police believe that both Tabish and Imtiaz are big catches and might have been involved in other blasts.
The police say six men planted 18 bombs all over Patna before Mr Modi’s rally.
All six have been identified, say the police, who allege that these men are members of the terror group Indian Mujahideen.
The six men were reportedly tasked with planting three bombs each at and near the rally venue, Gandhi Maidan. With the discovery of three bombs yesterday, police say all 18 explosives are now accounted for.
Seven exploded on Sunday, while the rest have been defused or detonated by bomb squads.
Among the six men named in the FIR is Tehseen Akhtar, a tech-savvy 23-year-old believed to be a top Indian Mujahideen operative and the mentor of Imtiaz Ansari.