Accusing Chancellor Helmut Kohl of breaking promises, tens of thousands of people rallied in eastern Berlin Saturday to demand that the government stem expected mass unemployment in the former Communist east.

The large crowd in central Berlin shifted the focus of growing protests from provincial eastern cities to the capital. Kohl, once the hero of German unification, is increasingly under fire as the economic situation in eastern Germany deteriorates.Reports in the past week showed the economy in former West Germany grew a robust 4.5 percent in 1990. But the east's 9 million workers are facing more than 30 percent unemployment or underemployment, the respected Institute for Economic Research said in a government-commissioned report.

It estimated that by the end of 1991, 1.5 million will be jobless and 1.6 million will be on "short work," meaning low pay for doing little. Average industrial output was 30 percent lower in 1990 than in 1989, the institute said.

Last Monday about 70,000 people joined rallies around eastern Germany. At least 50,000 people gathered in Leipzig, the heart of protests in 1989 that led to the fall of the Communist East German government.