Government soldiers and police sealed off opposition leader Joshua Nkomo's political stronghold in the western suburbs here today and began a house-to-house search for weapons and alleged insurgents.

The military operation, described by observers as the biggest ever seen in Zimbabwe's second-largest city, forced residents to remain in their homes and sent Nkomo into hiding. It also forced his party and that of fellow opposition politician Abel Muzorewa to cancel a public funeral they had planned for today of five of six followers killed during political violence last weekend.

It marked the third consecutive year that Prime Minister Robert Mugabe's government has mounted a military operation to quell opposition in this southern city and the surrounding Matabeleland region. It is also the latest in a series of attacks and counterattacks between government followers and opponents that have caused at least two dozen deaths in recent weeks as Zimbabwe prepares for its first national election since independence five years ago.

Several thousand soldiers surrounded townships housing more than 300,000 people after midnight, and residents later were warned by bullhorn to remain in their homes. Those caught outside the zone were allowed to return home, but no one was allowed to leave, according to witnesses and military officers.

Food shipments were cut off to the area, and doctors were barred from entering for several hours this morning, according to residents .

Information from inside the restricted zone was spotty. An unknown number of people were detained, and there were unconfirmed reports of scattered beatings during the joint police and Army sweep of the area. One witness said he saw civilians being loaded into a police bus this afternoon.

Officials of Nkomo's Zimbabwe African People's Union said they had no figures on those detained but said about 60 members of the party had been arrested earlier this week.

Journalists were barred from the area. Several were detained for brief periods for attempting to enter the zone, and four were warned by military officers and police to leave the city.

The government offered no explanation for the operation, except for a brief statement to the state-owned Zimbabwe Broadcasting Corp. from an unidentified police spokesman saying movement in the area was being "controlled" and that "residents are advised to remain in their homes."

Nkomo, whose home here is in the restricted zone, was escorted by followers out of the area to an undisclosed location last night before the soldiers arrived. "He's in Bulawayo, and he's safe, so far," said John Nkomo, publicity secretary for the Zimbabwe African People's Union and a member of Parliament who is no relation to the opposition leader. He said he and other party officials feared for Joshua Nkomo's safety.

John Nkomo charged that the military operation was designed to intimidate residents before the election, which is scheduled for June. But he said that while he had received scattered reports of mistreatment of those searched or detained, generally their treatment was "not as bad as they expected or as bad as it had been in the past."

At a press conference here today, Muzorewa said the military operation had been designed to "sabotage" the funeral ceremonies. "It was evil and wicked enough, painful enough, provocational enough, to have our people killed and destroyed like animals," he said. "But it is now even more disgusting and provocative to be refused to have a funeral and burial service for them."

Muzorewa accused the government of "complicity" in the killings, a charge government officials have rejected. At least two persons have been arrested in a police investigation of the slayings.

The crackdown follows incidents and allegations in Matabeleland and the Central Midlands regions reminiscent of charges of Army atrocities against dissidents during the past two years in which hundreds of civilians reportedly were killed.

Officials of Nkomo's party have alleged -- and western diplomats say they have received some confirmation -- of an increase in killings and abductions of Nkomo supporters by gangs of Mugabe followers brought into the area. At the same time, officials of Mugabe's Zimbabwe African National Union have charged that at least a dozen of their members have been slain in recent weeks by "dissidents" they contend are loyal to Nkomo.