KANDAHAR, Afghanistan -- Taliban militants rejected an offer of peace talks with Afghan President Hamid Karzai, saying yesterday there would be no negotiations until foreign troops leave Afghanistan.

Mr. Karzai offered Sunday to provide security for reclusive Taliban leader Mullah Omar if he enters negotiations and said the U.S. and other Western nations could leave Afghanistan or oust him if they disagree.

But Zabiullah Mujahid, a Taliban spokesman, said there could be no talks while foreign troops are in the country.

The White House made clear its distaste for the idea of talking with Taliban leaders right now, particularly Omar.

Mr. Karzai has dismissed the Taliban demand for foreign troops to leave, saying they are needed to keep Afghanistan safe.

BOGOTA, Colombia -- Colombia declared a state of emergency yesterday to crack down on illegal investment schemes that lured millions of people with promises of improbably high payouts, only to collapse amid rioting.

Government officials vowed to repay the poorest investors and sent police to shut down other alleged pyramid scheme operations yesterday, even though some loyal clients marched through the streets to defend companies that had offered interest rates as high as 150 percent a month.

The emergency authority lasts 30 days, and could be extended for 30 more.

Officials have said weak laws and legal maneuvering kept them from stamping out the fast-growing schemes earlier.

President Alvaro Uribe has expressed regret that authorities did not act sooner, and Colombia's top banking regulator resigned last week.

YANGON, Myanmar -- Courts in military-ruled Myanmar sentenced at least seven democracy activists to prison yesterday, continuing a crackdown that saw about 70 people jailed last week.

Four student activists, two members of the opposition National League for Democracy party and a former party member who has become a prominent independent activist received jail terms of 6 1/2 to 12 1/2 years at closed-door trials inside Yangon's Insein Prison, league spokesman Nyan Win said.

Authorities last week sentenced about 70 opposition activists, writers, musicians and Buddhist monks to jail terms ranging from 2 1/2 years to 65 years, with many of them transferred to prisons in remote areas.

The U.S. government criticized the military junta for arresting peaceful activists and putting them on trial.

STRASBOURG, France -- Zimbabwe's main opposition leader cautioned yesterday against imposing more sanctions on his country, instead urging immediate humanitarian aid.

Morgan Tsvangirai said that a Sept. 15 power-sharing agreement with President Robert Mugabe could still yield results despite fundamental disagreements between the two sides.

But Mr. Tsvangirai said an offer for his party to head the finance ministry was a trap. Mr. Tsvangirai, who was in France for an international development conference, said his party should be given more power over internal security.

Mr. Tsvangirai said that, instead of more sanctions, the country must have emergency humanitarian aid. He said millions of people need food and medicine to counter the spread of cholera.

The EU has blacklisted 172 people linked to Mr. Mugabe's government and four companies believed to financially support Mr. Mugabe and his ZANU-PF party.