Attend an evening with Andre Agassi
The two countries agreed as early as 2004 to establish a hotline between their foreign ministers in case of an accidental nuclear launch, but neither side could clarify today whether the link was up and running.
If Mr Mukherjee had wanted to call Pakistani leaders, the standard protocol would have been for him to telephone his counterpart, rather than the President, and to arrange the call through the Indian High Commission in Islamabad, which would tell the Pakistanis which number to expect a call from.
Sherry Rehman, Pakistan's Information Minister, issued a statement denying that the usual verification procedures had been bypassed.
She said Mr Zardari had received a "threatening" telephone call from "a verified official phone number of the Indian Ministry of External Affairs".
She did not say that it was from Mr Mukherjee, but other Pakistani officials insisted that it was.
Mr Mukherjee, however, denied that the caller was him, saying that India had been informed about the hoax by "friends from third countries".
"We immediately clarified to those friends, and we also made it clear to the Pakistan authorities, that I had made no such telephone call," he said.
"It is, however, worrying that a neighbouring state might even consider acting on the basis of such a hoax call, try to give it credibility with other states, and confuse the public by releasing the story in part.
"I can only ascribe this series of events to those in Pakistan, who wish to divert attention from the fact that a terrorist group operating from the Pakistani territory, planned and launched a ghastly attack on Mumbai."
He did not comment on the allegation that the call came from an official Indian foreign ministry number, but Indian government sources said that was unlikely.
"We're not living in a day and age when you can just look at the number flashing up in front of you and assume the call is coming from there," said one Indian official.
India has said it is not considering military action against Pakistan despite mounting political pressure on the government to appear tough on terrorism in the run-up to national elections, due by May.
But Wajid Shamsul Hassan, Pakistan's high commissioner in London, confirmed that Pakistan's government was bracing for an Indian military strike immediately after the Mumbai attacks.
"There was circumstantial evidence that India was going to make a quick strike against Pakistan to teach her a lesson," he told the BBC.
"This is what we were told by our friends - that there could possibly be a quick strike at some of the areas they suspect to be the training camps, an air raid or something of that sort."
In the first sign that Islamabad was preparing to clamp down on militants linked to the Mumbai attacks, Pakistani forces last night took over an LeT camp near the Kashmiri town of Muzaffarabad.
Wars and peace
1947 Partition of India and Pakistan
1947-48 Year-long war after Pakistan supports Muslim insurgency in Kashmir
1965 Pakistan launches covert offensive; UN brokers ceasefire
1971 War between East and West Pakistan. India invades in support of East Pakistan, which becomes Bangladesh
2002 India blames Lashkar-e-Taiba after attack on Indian parliament kills 14
Source: Times archives
Industry sectors news at a glance. Interactive heatmap, video and podcast
Everything the Business Traveller needs to know to make a better trip
Get ready for the winter sports season, with our resort guides and snow reports
We are backing British business, what is the confidence of the nation and what businesses are succeeding?
Growing demand for energy, oil that is harder to reach and the rise of carbon dioxide emissions. We examine the energy challenge
With rail travel in Europe on the rise, we review the benefits of travelling by train
Enjoy further reading from Travel to Fashion, Business to Sport, discover more
Shortcuts to help you find sections and articles
1998
£47,955
12 months for the price of 11 and a 5% discount.
Offer ends 31/11/09
Check your free Experian credit report before applying
Car Insurance
to £60K + bonus (OTE £90k)
Lord Search & Selection
Location Flexible
PwC’s Consulting practice helps businesses of all shapes
and sizes work smarter and grow faster.
£85k
CPA
Highly Competitve
Specsavers
Whiteley, near Southampton
Moments from Battersea Park.
For sale with Winkworth
Find out about shared ownership.
See your free Experian credit report beforehand
7nts - Penang £499; Borneo £699; All Inclusive £799 including flights, taxes, accommodation and private transfers
For your ultimate tailor-made ski holiday, click here
Get covered on your travels with a superb range of policies at great prices. Visit InsureandGo.com
World Class Golf, Spa and preferential Beach Club. Private estate overlooking West Coast
Villas from £275 per night inclusive of Golf
Contact our advertising team for advertising and sponsorship in Times Online, The Times and The Sunday Times, or place your advertisement.
Times Online Services: Dating | Jobs | Property Search | Used Cars | Holidays | Births, Marriages, Deaths | Subscriptions | E-paper
News International associated websites: Globrix Property Search | Milkround
Copyright 2009 Times Newspapers Ltd.
This service is provided on Times Newspapers' standard Terms and Conditions. Please read our Privacy Policy.To inquire about a licence to reproduce material from Times Online, The Times or The Sunday Times, click here.This website is published by a member of the News International Group. News International Limited, 1 Virginia St, London E98 1XY, is the holding company for the News International group and is registered in England No 81701. VAT number GB 243 8054 69.