Zimbabwe's President Robert Mugabe has said liberation war veterans would take up arms if he loses a 27 June presidential run-off vote.
Mr Mugabe told youth members of his ruling ZANU-PF party in Harare that the veterans had told him they would launch a new bush war if the election was won by opposition leader Morgan Tsvangirai, whom he accuses of being a puppet of the West.
The statement is the latest ratcheting up of pressure to extend his 28-year-presidency.
Mr Tsvangirai, human rights groups and Western powers accuse President Mugabe of unleashing a brutal campaign to win the run-off after he lost presidential and parliamentary elections on 29 March.
Mr Tsvangirai fell short of the majority needed to win the presidency outright in that vote. He says 66 of his followers have been murdered since.
But former guerrilla commander Robert Mugabe, president since independence from Britain in 1980, blames the MDC for the violence which has caused widespread international concern.
The war veterans, usually acting alongside the ZANU-PF youth militia, have regularly been used to intimidate President Mugabe's opponents and were involved in implementing the government's seizure of thousands of white-owned farms beginning in 2000.
Some of the seized land was given to the veterans.
Earlier, the MDC said Zimbabwean police impounded two campaign buses used by Morgan Tsvangirai in the latest action against the opposition leader in the election campaign.
Mr Tsvangirai, who has been detained four times in the past week and has had his own vehicle confiscated, would continue the campaign.
Meanwhile, the UN Emergency Relief Coordinator says the humanitarian situation in Zimbabwe is worsening with up to 4m people, a third of the population, in need of aid.
John Holmes, who heads the UN Office for the Coordination of Humanitarian Affairs, told the UN Security Council that only a quarter of the country's needs were likely to be met by the forthcoming harvest.
He said he had briefed the council in closed session on what he described as a 'very worrying, very serious and deteriorating' humanitarian situation.
People in Zimbabwe are increasingly in need of help due to their difficult economic straits and the collapse of social services there, he added.
'Against that background ... the decision by the government to suspend field operations by international NGOs and private volunteer organisations working in Zimbabwe was particularly regrettable,' Mr Holmes said.
'I deplore that decision and I hope very much they'll rescind it in the very near future.'
Zimbabwe's government has provoked international outrage by suspending all aid work after accusing NGOs of siding with the opposition.
His comments came as the US accused Zimbabwe's security forces of seizing its aid and distributing it to supporters of President Robert Mugabe.
US officials charged yesterday that Zimbabwean authorities had last week 'hijacked' a truck of US food aid for hungry school children and handed it to government party members.
Mr Mugabe's government said aid groups would only be allowed to resume operations if they pledged not to interfere in politics, accusing them of openly siding with the opposition Movement for Democratic Change party in the build-up to the 27 June voting.
Relations between Western aid groups and the Mugabe regime have long been strained, with the Harare government previously forcing aid groups to channel their efforts through local officials.
