While only the completion of investigations would reveal if the architects of the Mumbai train blasts have any link to Nepal, many terrorists targeting India have used the Himalayan country either as a getaway or transit to plan attacks in the past.
Two Pakistanis, Ghulam Hussain Cheema and Aftab Mahaddin Siddiqui, were arrested in the capital on Thursday after police received an alert that the two men, wanted in connection with a five-year-old case involving a senior Pakistani diplomat caught with 16.5 kg of RDX, had resurfaced in Nepal.
The timing of the two men's arrival in the Nepal capital could have a link to the seven blasts in local trains in Mumbai on Tuesday or new activities of Pakistan's intelligence agency ISI.
In the past, a number of terror attacks in India turned out to have a Nepal connection.
Three men held responsible for a deadly explosion in a market in New Delhi in April 1996 were based in Maharajgunj in Kathmandu.
Latif Ahmed Waja, Mirza Nissar Hussain and Mahmood Kille were arrested in India in June 1996 after the blast killed 21 civilians in the Lajpat Nagar central market.
Following their arrest, Nepal police recovered around 20 kg of explosives, including RDX, timer pencils, detonators and remote control devices, from Kathmandu's Swayambhu area, known as one of the holiest Buddhist pilgrimage sites.
The trio belonged to an extremist group, Jammu and Kashmir Islamic Front, and had been coached in Nepal by the Dawood Ibrahim's Pakistan-based associate Tiger Memon.
Five months after their arrest, three more men from the same outfit, Fayaz Ahmed Shah, Gulam Rasool Mir and Azaz Ahmed Chowdhary, were also arrested in India.
The three were operating from the upmarket Lazimpat area in Kathmandu and were trying to launch terrorist strikes in India on January 26, 1997, during the Republic Day celebrations.
In January 1997, Indian police arrested Javed Pawle alias Mohammed Shakeel, an IS-trained extremist designated to set off a blast at Mumbai's World Trade Centre.
Shakeel had arrived in India via Nepal and his arrest led to raids by Nepal police who unearthed a hoard of RDX, other plastic explosives and detonators.
Besides Kashmiri terrorists, Sikh extremist groups funded by the ISI have also been operating from Nepal.
In 1998, Lakhbir Singh, associated with the outlawed separatist Khalistan Zindabad Force was arrested from a hotel in Teku area with about 20 kg of RDX.
During interrogation, Singh confessed he had received the explosives from three Pakistani Embassy officials, later identified as counsellor Ejaz Hussain Minhas, first secretary (consular) Mohammed Arshad Cheema and Asam Saboor.
Both Saboor and Cheema were expelled by the Nepal government.
Cheema, deported in 2001 after being caught red-handed with 16.5 kg of RDX, is also said to be involved in the hijacking of an Indian Airlines flight from Kathmandu to Kandahar in 1999.