Zimbabwe's President Robert Mugabe has accepted defeat in a referendum on a new constitution.

"The government accepts the result and accepts the will of the people," the president said in a televised address to the nation.

He added that the result was "unfortunately a 'no' vote".

Opponents of the president secured 697,000 votes in the weekend referendum, while the president's supporters garnered only 578,000.

The proposed constitution would have consolidated presidential powers and allowed the government to confiscate white-owned land for redistribution to black farmers without compensation.

The referendum was seen as a barometer of the deeply unpopular government. The opposition has predicted that the government now faces defeat in elections due in April.

The referendum turn-out was low and a split emerged between urban areas, where the vote was overwhelmingly no, and rural areas, where the yes vote dominated.

Constituencies in the capital, Harare, where discontent with President Mugabe's government is greatest, registered the biggest numbers against the proposed new constitution.

The government had campaigned tirelessly to ensure it won the vote for constitutional change, with a big advertising campaign.

The BBC's Grant Ferrett, reporting from Harare, says the recent dramatic decline of the economy undoubtedly played a large part in the defeat.

Under the referendum act, President Mugabe is not obliged to respect the outcome of the vote, but before the vote he promised to do so.

Vote-rigging allegations

Earlier, opposition leaders had warned of the possibility of vote-rigging - a charge they have repeatedly levelled against the government.

Lovemore Madhuku, of the National Constitutional Assembly (NCA), said President Mugabe was corruptly seeking to strengthen his position while ignoring criticism of the draft constitution.

Eight opposition activists were released on Tuesday, after being detained while distributing leaflets in Harare during the vote.

They were accused of illegal campaigning and incitement to violence.

Jonathan Moyo, a spokesman for the government-sponsored Constitutional Commission which drew up the controversial draft, said he was surprised by the level of opposition in the towns.

'Vote for colonialism'

President Mugabe and his ruling party encouraged voters to support the draft constitution, saying that its rejection would be a vote for colonialism.

A full page advertisement in the main government-run newspaper showed a white couple wearing Vote No T-shirts above the words: "Don't follow them back to the dark days of the past, when they were kings and queens."

The new draft constitution was drawn up by a 400-member commission appointed by the government and dominated by its supporters, and would have replaced the independence constitution provided by the UK at independence 20 years ago.

Although land reform has dominated the campaign, the government has faced severe criticism over its handling of the economy.