KABUL - Taliban militants headed into cities across Afghanistan on Sunday as they celebrated their Eid ceasefire with feasts and selfies, raising questions about what happens when the ceasefire ends at midnight.President Ashraf Ghani said he would extend a government ceasefire on Saturday and urged the Taliban to do the same, winning praise at home and international backing, but critics said his overtures had allowed the Taliban to pour into cities unchecked.The Taliban said there would be no extension.Ghani had committed "a grave mistake" by allowing Taliban fighters to enter government-controlled areas, said Amarullah Saleh, a politician and former head of the National Directorate of Security."We don't have mechanisms in place to mitigate the breach of ceasefire by the Taliban," Saleh told Reuters.Members of parliament opposing Ghani's move said he had not consulted politicians and would be left with no recourse if the Taliban rejected his impromptu request.A senior Western diplomat in Kabul said Ghani's decision was "a bold move" but questioned what happens if the Taliban do not extend their unprecedented halt in hostilities against government forces."The consequences could be disastrous," he said.The Taliban said their members were expected to leave government-controlled areas before sunset.A suicide bombing in Jalalabad, close to the governor's office in Nangarhar province, killed at least 18 people on Sunday and wounded scores, an official and doctor said.No group immediately claimed responsibility.A car bomb killed 36 people at a gathering of Taliban and Afghan armed forces in the same province on Saturday. Islamic State, not covered by the government ceasefire, claimed responsibility for that attack.FEASTS AND MUSICOver the weekend, ecstatic men and children crowded around the soldiers and Taliban fighters, some of whom had checked in their weapons at the entrances to cities, and urged them to turn their ceasefire into a permanent peace.Governors and senior government officials hosted small feasts, played music to welcome the militants, coinciding with the close of the month-long Ramadan fasting season."There is no intention to extend the ceasefire," Taliban spokesman Zabihullah Mujahid told Reuters. ."..Our normal operations will start tomorrow (Monday).”Ghani's office has yet to declare a new timeframe for the extended government ceasefire.Western diplomats based in Kabul said they were issuing fresh travel warnings for the whole country."The Taliban can always use a ceasefire as an opportunity to attack foreigners," one Western diplomat said. "Nobody has any clue how many Taliban militants are now hiding in civilian areas."US Secretary of State Mike Pompeo, echoing Ghani's announcement on Saturday, said peace talks would have to include a discussion on the role of "international actors and forces." "Ghani has full blessings of the US administration and it is crucial for the US officials to prove that (US President Donald) Trump’s policies are working and talks with the Afghan Taliban are imminent," said a senior diplomat who met Afghan officials on Sunday to monitor the chance of back-channel talks with Taliban leaders."POSITIVE RESPONSE"The United States wants Pakistan, which it accuses of harboring Afghan Taliban commanders, to exert more influence on the group to bring it to the negotiating table.The only time direct talks between the Afghan government and the Taliban have been held, in 2015, they broke down almost immediately.The Taliban are fighting US-led NATO forces, combined under the Resolute Support mission, and Ghani's U.S.-backed government to restore sharia, or Islamic law, after their ouster by US-led forces in 2001.But Afghanistan has been at war for four decades, ever since the Soviet invasion in 1979."What we witnessed over the last two days was an overwhelmingly positive response by all Afghans to peace," Lt-Colonel Martin O'Donnell, a spokesman for Resolute Support and US Forces-Afghanistan, told Reuters."Not even the attack on peace yesterday in Nangarhar by the enemies of Afghanistan will slow the nationwide momentum or quiet the celebration of a long-overdue cessation of hostilities and a chance for lasting peace."The Taliban roam huge swaths of the country and, with foreign troop levels of about 15,600, down from 140,000 in 2014, there appears little hope of outright government victory.