The South African government today claimed victory over what it said were black nationalist plans to launch a large-scale insurrection coinciding with yesterday's anniversary of the 1976 Soweto uprising. Eleven blacks reportedly died in overnight violence, one of the highest casualty tolls in several weeks.

The millions of black workers who stayed away from their jobs to mark the anniversary went back to work today, and life gradually returned to the country's paralyzed cities. The heavy security force presence in Soweto and other black townships was reduced somewhat. The government expanded its controls over news reporting of the situation, however, issuing a ban today on all live television broadcasts by foreign networks, as well as live TV or radio interviews with South Africans.

Spokesman Leon Mellett acknowledged at today's Bureau of Information news briefing in Pretoria that the 11 overnight deaths, including four blacks shot by police, reflected an increase in violent incidents. They bring to 42 the number of deaths related to unrest since the state of emergency came into force last Thursday.

Official spokesmen asserted that stability had been restored, and the rand rose slightly on foreign exchange markets with the help of active buying by the country's central bank. It reached 40.15 cents, compared with a near-record low of 36.55 cents a week ago.

Finance Minister Barend du Plessis announced a long-awaited package of measures designed to boost the economy, which won some qualified applause from the otherwise despondent business community.

Describing the emergency declaration as a "well-calculated action," du Plessis said indications were that it "has already started to exercise a stabilizing effect on the economic and financial terrain."

Mellett told today's briefing in Pretoria that the government's firm action had thwarted plans by the underground African National Congress to launch "a massive popular and multipronged offensive" on Monday. The violence had not materialized, he said.

"There is optimism among the many law-abiding people of South Africa and this trend should continue," Mellett added.

Mellett said that there had been an average of 8.4 unrest-related deaths a day since the emergency was declared, compared with five a day for the first five months of this year. Two days ago, the bureau said that there had been a 35 percent drop in incidents of unrest since the emergency regulations came into force.

The stringent press controls that were introduced with the emergency and tightened yesterday were further extended today.

President Pieter W. Botha issued a proclamation extending the restrictions to the nominally self-governing tribal "homelands" as well as the urban townships, and all live satellite transmissions by foreign television networks were banned for the duration of the emergency.

A directive was also issued prohibiting live television and radio interviews with South Africans.

This week's edition of Newsweek magazine did not appear in South Africa, United Press International reported. Bureau chief Richard Manning said the magazine's distributor had been told by the Bureau for Information not to bring it into the country, UPI said.

This story was written under the announced press restrictions.

The first foreign newsman to be expelled from the country since the emergency began left Johannesburg airport tonight after failing in a last-minute appeal to the provincial Supreme Court here.

Wim de Vos, a Dutch-born CBS cameraman, was expelled Friday but allowed to appeal yesterday to the Minister of Home Affairs, Stoffel Botha. Botha rejected the appeal and ordered de Vos to leave the country by tonight.

CBS appealed to the Supreme Court to defer the expulsion order, but Judge Andre van Niekerk ruled that he had no power to do so.

Four West German nationals also were expelled today after being detained under the emergency regulations.

In Washington, the State Department said that the South African government had given permission to the U.S. Consulate in Cape Town to visit Scott Daugherty, 18, of San Diego, one of two Americans being held under the emergency.

In Australia, the government today expelled a South African diplomat accused of hitting a woman protester who entered the grounds of the embassy in Canberra.

The diplomat, administrative attache J. E. Alberts, reportedly was seen on television striking Kirsti Valiaho, 22, with a stick as she climbed over an embassy wall and broke windows in the building Monday. Valiaho was among 200 persons demonstrating to mark the Soweto anniversary.

Australian police charged her with damaging embassy property, but Australia's acting Foreign Minister Gareth Evans told South African officials that Alberts' behavior was "unacceptable by Australian standards."