Armed with automatic weapons, Tanzanian paramilitary unit is now patrolling the Kenya-Tanzania border.

Relations between the neighboring states have sunk to a new post-independence low during the past week since Tanzania's Minister for Home Affairs Hassan Moyo announced that their 450-mile border would be permanently sealed.

Tanzania first closed the border in early February and impounded several million dollars' worth of Kenyan vehicles and private aircraft, but Kenya has not retaliated.

"As far as we are concerned," said a Kenyan immigration official here at the border, "Things are normal. We are open 24 hours a day."

He conceded, however, that during the past week only four vehicles crossed his post.

Yesterday, two journalists who came to Namanga to report on the border situation for Finnish television were arrested by Tanzanian authorities while filming a sign that reads "Welcome to Tanzania."

The tension between Kenya and Tanzania grew out of the collapse of East African Airways in January. The two countries and Uganda had owned the airline jointly.

Kenya subsequently started its own airline with leased Boeing 707s and three DC-9s salvaged from East African Airways. Tanzania plans to inauguarate its own national carrier next month.

Delegations from the two countries met twice last month in an effort to normalize relations.

Kenya has asked that its property be returned immediately and that assets of the near-dead East African Community be divided as the courts may decide. All of the Lake Victoria steamers and most of the community's aircraft were in Kenya when the community fell apart early this year.

Tanzania, however, wants to use the ships and planes and has tied the return of Kenyan property to the immediate division of the community's movable assets.

All of the Community's assets were jointly paid for by the three partner states.

The cooperation of socialist Tanzania and capitalistic Kenya in the East African Community had been something of an anomaly.

Kenyans seem bewildered at the permanent closing of the border, and there is a widespread feeling that the move had more to do with politics than with economics.

Nairobi's Weekly Review speculated that "In order for socialism to succeed, Tanzania must seal itself off from all capitalistic influences, and not just capitalistic goods."

President Julius Nyerere of Tanzania told his countrymen yesterday that the breakup of the Community was a major setback for the country's development plan and that large new infrastructure investments must urgently be made now.

Tanzanian customs and immigration officials admit that they are now virtually powerless and that their post and the border area has been controlled by the paramilitary unit for about a month.

On Tanzanian who has worked as a driver for the same concern in Kenya for 20 years was caught in Tanzania when the surprise closure announcement was made. He said that troops set up a roadblock 20 miles from the border and told him nobody could pass without a special reason.

The driver made an excuse to get to the next town and then walked the remaining 17 miles through the bush to get back to Kenya.

From here at Namanga it appears that Tanzania could be preparing for a long spell of stormy relations with Kenya.

"Tanzanians are our friends and neighbors," said a Namanga shopkeeper, "but now we feel that the Tanzanian government is our enemy."