Leaders of Pakistan's coalition government are setting about seeking a replacement for former president Pervez Musharraf and tackling pressing economic and security problems.
Mr Musharraf, a former army chief, resigned on Monday night to avoid impeachment nearly nine years after seizing power in a coup.
A new president must be chosen by Parliament and the countryy's four provincial assemblies within 30 days.
Old rival India reacted cautiously to his resignation. Pakistan is committed to a peace process with India launched under Mr Musharraf, but India fears a weak civilian government will not have his influence over the army and military spy agency, which India believes is behind most terrorist attacks on its soil.
Mr Musharraf left his official residence in Islamabad after announcing his resignation during a televised address. He reviewed a guard of honour before his departure.
During his national address on Monday, he said he was confident the charges would not stand, but that now was not the time for more confrontation.
He is accused of violation of the constitution and gross misconduct.
The United States praised him as a committed partner against terrorism and pledged after his resignation on Monday to keep a good relationship with the new government and fight extremism together.
However, the Afghan Foreign Ministry said the resignation would strengthen democracy in Pakistan and Afghanistan.
Televised address
During a long defence of the country's economic record and the progress it had made since he seized power, a stony-faced Mr Musharraf said on television: "Pakistan first has been my philosophy", adding that he had worked in "good faith" in the face of challenges including militancy and economic problems.
"Unfortunately, some elements acting for vested interests levelled false allegations against me and deceived people. They said that during the last nine years our economic problems and electricity shortages were due to our policies. It is absolutely wrong and deception for the country.
"They never realised that they could be successful against me, but they never thought how detrimental it would be for the country."
The coalition of parties that won elections in February, led by the party of slain former prime minister Benazir Bhutto, finally overcame months of divisions and agreed to impeach Mr Musharraf.
However, Mr Musharraf said that there was now law and order in the country, that human rights and democracy had been improved and that Pakistan was now an crucial country internationally. "On the map of the world, Pakistan is now an important country, by the grace of Allah."
Hospital blast
Meanwhile, a bomb has gone off in the compound of a hospital in northwest Pakistan on Tuesday, killing 20 people.
"We don't know whether it was a suicide attack, but the bomb went off in the compound. I have initial reports of 20 dead," said Syed Mohsin Shah, a senior city government official.
Supporters of a Shi'ite Muslim leader were protesting outside the hospital in the town of Dera Ismail Khan when the bomb went off. The Shi'ite leader was shot dead earlier on Tuesday and his body taken to the hospital.
