After weeks of bickering and name-calling Tanzani abruptly closed its border with Kenya today, stranding hundreds of American and European tourists.

All air, sea and land transportation has been cut by Tanzania, which has impounded Kenyan-registered airplanes and vehicles.

No Kenyan-registered plane may overfly Tanzanian territory without security clearance. At least a dozen Kenyan-based private planes are reported to have been confiscated in Tanzania.

The Kenya Minister of Tourism, Mathews Ogutu, said at least 50 Kenyan tourist vehicles are being held in Tanzania and that their drivers have been detained.

Several hundred tourists are reported confined to their hotels while others are said to have been arrested.

Tanzania took the action just a few hours after Kenya announced the formation of Kenya Airlines yesterday. Tourists who crossed from Tanzania to Kenya early yesterday reported no incident, but those who tried to leave later in the day were turned away from the border by Tanzanian immigration officials.

The Tanzanian government offered no explanation of its action, but it is widely believes to be a response to the inauguration of Kenya Airlines.

Tension between the two countries has been mounting for weeks as each blamed the other for the collapse East African Airways. Last week the airlines, owned jointly by Kenya, Tanzania and Uganda went bankrupt and ceased operation.

The Tanzanian press accused the Kenyans of plotting to destroy East African Airways to "satisfy" their lust for getting rich quickly."

Another theory is that the border was sealed in preparation for twin celebrations marking the formation of a new political party in Tanzania and also the 10 anniversary of the country's socialist system.

Senior Tanzanian officials, who are attending the celebrations on the island of Zanzibar, were unavailable for comment.

Dignitaries from all over the world, including the new U.S. ambassador to the United Nations, Andrew Young, are attending the celebrating.

Earlier this week Kenya withdrew its delegation to the celebrations.

About 20 American journalists covering Ambassador Young's African tour are apparenlty stranded in Tanzania as most onward air connections are made via Nairobi.