RJD chief Lalu Prasad and senior BJP leader Sushil Kumar Modi crossed swords on Twitter on Friday over the state of the Indian Railways.

Lalu, a former railways minister, first attacked Prime Minister Narendra Modi for the revenue loss in the country's lifeline.

"Indian Railways is rapidly slipping into a financial morass and terminal debt trap. To avert the impending tragedy, it time to think anew," Lalu tweeted.

The trigger was probably the Prime Minister's address to railways employees via video conferencing at the Rail Vikas Shivir in Surajkund on the outskirts of Delhi. Modi said the railways should focus on "new speeds, progress and new capacity" along with gaining financial strength, and that he had special affection for the railways because he had spent much of his early days at railway platforms.

Replying to Lalu's tweet, Sushil shot back: "@laluprasadrjd milked railways like cow but Modiji know Rlys better than you bcose he served tea with milk on platform."

Lalu, never one to take things lying down, retorted: "What a rubbish logic! Do u kw wat happens when u don't milk a Cow?..cow falls sick..& this is wat happening now.. Samjhe ki nahi".

He followed that up with a two-tweet barrage: "U mean if smbdy selling tea at plateform is a railway expert & can turn railway in profit then ask PM to appoint all tea sellers as advisors to railways & gv all tea sellers across India class1 officers facilities,so tht railway gets into profit."

The former deputy chief minister did not back down. He tweeted at Lalu: "Are you blaming Nitish Kumar for the so called mess of Rlys bcose you inherited from him? You claim you brought turn around in Rlys then why failed miserably in Bihar? Ask Nitish kumar about your tenure as Rly Minister? Is he ready to give you certificate?"

After that Lalu cited figures about the mess the railways are in. Here's one sample: "Modi Ji, For the first half ending September, railway's Gross Traffic Earnings hv declined by 4.5% as against targeted growth rate of 13% Railways operating ratio has deteriorated to 114%. It is likely to report net loss of Rs 25,000 crore in the current year."

This is not the first time Lalu has attacked the Prime Minister over the railways situation; earlier too he had slammed Modi on the subject and even written to railways minister Suresh Prabhu.

"It is tragic that IR proposes to increase financial leverage by $75 billion that too for un-remunerative projects like bullet trains," Lalu tweeted.

Sushil replied: "Laluji is opposing Bullet train but his govt in Bihar will spend 16 K cr for Metro.Will his party oppose Metro also?"

Another Sushil retort, in Hindi, was: "Nitish used to say that during the RJD regime people used to feel embarrassed calling themselves Bihari and during the BJP regime people used to feel proud."