How will Bhutto's killing affect this fragile country?

Q: What are the likely political repercussions in Pakistan of Benazir Bhutto's assassination?

The killing has dealt a severe blow to the fragile hopes of an orderly transition to democracy in Pakistan and has left the country facing a dangerous future. Despite the repression which followed the imposition of the state of emergency by President Pervez Musharraf, the West had accepted his protestations that "free and fair" elections were back on track. Indeed Mr Musharraf as president, with Ms Bhutto as prime minister, was the ideal combination sought by the US and Britain.

The murder in Rawalpindi, and the anger it has unleashed, has led some political leaders, such as Riaz Malik of the opposition Pakistan Movement for Justice Party (Tehreeke-insaf) to warn of civil war. Even if this is too alarmist, and there is no outbreak of full-scale fighting, there will be unease among the international community at the prospect of upheaval in a nuclear-armed state with militant Islamist groups waiting in the wings.

Q: Will the scheduled elections go ahead? What would be likely to happen if they are cancelled?

President Musharraf called an emergency meeting of his cabinet to consider whether the elections on 8 January will now be held. Nawaz Sharif, another former prime minister who has returned from exile to contest the polls, also said they may have to be postponed. But he does not command the popular support Ms Bhutto had enjoyed, and was unlikely to come out a winner at the ballot box.

A prolonged delay in the elections, with President Musharraf and the army ruling the country, is likely, however, to lead to widespread protests. The former general is already in confrontation with opposition figures, ranging from lawyers and students to Islamist militants. America and Britain would also find it harder to support indefinite military rule.

Q: Who is being blamed over the assassination?

In a nationwide television address, President Musharraf yesterday called for calm and blamed the murder on "terrorists". But even while he was speaking, Ms Bhutto's followers in the Pakistan People's Party were burning buses and buildings and accusing the President of being responsible for her death. Although Islamic fundamentalists were the immediate suspects, Ms Bhutto's supporters claim elements of the military and the secret police were conspiring against her. After surviving a previous bomb attack, within hours of her return to Pakistan, she had claimed figures with official connections were involved.

Any evidence of collusion in her death by the military is sure to prompt bloodshed. Nawaz Sharif, who had rushed to the hospital where Ms Bhutto died, told her supporters: "I will be with you to take revenge for her death ... We will take revenge on the rulers."

Q: What are the implications for the region?

Violence and unrest in Pakistan is unlikely to be confined to its borders. The conflict in Afghanistan with the US, Britain and other Nato countries engaged in a bitter battle is intrinsically linked to Pakistan with the Taliban using the country as a base and recruiting centre to carry out attacks.

The Afghan President, Hamid Karzai, as well as American and British officials, had accused Pakistani officials, especially members of the intelligence service, of aiding the Taliban. Swathes of territory on the Pakistani side of the border have become "Talibanised", and Islamist groups, which have already carried out several assassination attempts on President Musharraf will, if Pakistan should implode, be able to widen the range of jihad across frontiers.

Q: What are the implications for the war on terror?

In condemning the assassination, George Bush and Gordon Brown stressed it must not be allowed to derail the road map towards democracy. But officials in Washington and London admit that is now a real danger, and attempts to bring stability to Pakistan, a country of immense importance to the "war on terror", have suffered a massive setback.

The West, in the short term at least, will continue to back Mr Musharraf. However, if there are signs he is losing control, or the accusation continues to grow that he is the cause and not the solution to Islamist terrorism, they make look for another leader to back.