The students were trapped in the school located at Pandarsoli on the Haldipokhar-Kowali Road in Kowali police station area since Saturday night after the premises got flooded due to heavy rain.
Former Janata Dal-United president R C P Singh joined the Bharatiya Janata Party on Thursday in the presence of Union minister Dharmendra Pradhan, after which he accused Bihar Chief Minister Nitish Kumar, once his mentor, of compromising with crime and corruption in his pursuit of "kursi" (chair).
Asserting that the prime minister's job will remain with BJP leader Narendra Modi even after the general elections slated for next year, Singh claimed the country is scaling new heights under PM Modi's leadership.
During a cabinet meeting earlier in the day, Modi lauded both Naqvi and Singh for their contributions to the country during their ministerial tenure, sources said.
"You should go and ask Giriraj whether the use of such language is nyaysangat (proper)," said Kumar, a stickler for propriety in public behaviour, with a broad smile barely concealing his detestation.
In April, another Indian medical student was attacked on the same spot.
St Petersburg has a large foreign student population and is known for attacks on foreigners and extreme nationalism.
Indicating a rift within the party after its split with the ruling Janata Dal-United in Bihar, a Bharatiya Janata Party member of Legislative Assembly on Wednesday said that state Chief Minister Nitish Kumar would be a "better" prime minister than Narendra Modi and blamed his party for the break up of the coalition.