Larkana, Pakistan — The protesters against President Zia's regime come from many backgrounds. Outside the town of Larkana, the northern Sindi city gripped by political violence now entering its third week, a group of protesters included older women in the long shirt and baggy trousers that are Pakistan's national dress and young students who were bearded and vocal in their anger.
There were also the ''sardars,'' or tribal elders, the feudal landlords, and the ''pirs'' and ''mirs'' - the hereditary religious leaders of Pakistan's volatile province of Sind.
They gathered at the gravesite of Zulfikar Ali Bhutto. Former Prime Minister Bhutto was a native of Larkana. A powerful politician, he was overthrown as prime minister and then executed in April 1979 by the martial law government of Gen. Mohammed Zia ul-Haq.
Police moved in to disperse last Sunday's gathering with teargas cannisters and lathi sticks (a club of bamboo and iron) at the ready, if it was necessary to charge. At least 15 persons were arrested, according to a government spokesman, including two members of the Bhutto family.
The protest near Larkana was the most personal - if indirect - confrontation yet between the two men, Bhutto and Zia, who have galvanized the Sindi body politic.
In a surprisingly strong, rural mass movement in Sind - the first such political movement outside the cities that Pakistan has seen - thousands have continued their defiance of General Zia's martial law regime. At least 38 people have died in the protests. According to opposition sources, 80 are dead. The opposition claims 7,000 have been arrested or successfully ''courted arrest.'' The government acknowledges that some 1,400 Sindis are under arrest.
Driving through Sind's interior, where slate hills turn to desert and large tracts of rice, wheat, and cotton fields are flooded by monsoon rains, one is struck by the poverty. There are few development programs here.
People live on the margin of an agricultural economy. One passes through a score of hamlets and villages hugging the banks of the Indus River.
In recent weeks, they have all, in one way or another, protested against the Zia regime or gone on the rampage. They have defied police lines, been beaten back by teargas or a lathi charge. They have burned government buildings, disrupted transportation links, broken into Sindi jails and court buildings, or engaged in general strikes.
Inside the dirty, overcrowded jail in Dadu, one of Sind's most violent, up-river towns 200 miles from Karachi, 77 political prisoners told why they were willing to defy martial law, endure flogging, and go before special military courts-martial whose sessions last less than five minutes.
Their reasons for submitting to the punishment are as eclectic as the four provinces of Pakistan.
The province of Punjab, they acknowledge, is the key to the longevity of the Zia regime. If the country's most populous province, its breadbasket and dispenser of army positions and posts in the federal bureaucracy, does not enter the protest, Zia and his army will probably be able to control the situation here in Sind.
But, that is not the end, they add quickly. In Sind, the fuse has been lit. And, if the protest is confined within this southern province's borders, if others do not join, it will give far greater impetus to the more radical voices favoring Sindi independence, a movement called ''Sinduh-Desh.''
All of the young men crammed into one of the barracks of Dadu's prison want to speak. They include medical students, provincial government civil servants, workers, shopkeepers, and peasants. Most are supporters of Mr. Bhutto's Pakistani People's Party, which has always dominated the politics of Sind. Others belong to the ''Sinduh-Desh'' movement or are followers of the traditional ''sardars'' or hereditary ''pirs.''
Some are political protesters, demanding a return to democracy and the end of martial law, others are protesting Zia's Islamization program - most interior Sindis are Sufi Muslims who charge that General Zia has made heresy of the Koran. Still others are there at the behest of their ''sardars,'' who have refused to pay the Islamic ''usur'' land tax, on their vast holdings, which dominate the Indus River valley of Sind. Some are here because they went to the streets to avenge Mr. Bhutto's death. Others are followers of G. M. Sayed, the father of Sindi nationalism, a hereditary ''pir,'' who is the guiding force behind the Sinduh-Desh movement.
Strangers here are eyed with suspicion. But when people discover a journalist , they immediately want to talk. It is not surprising that their primary topic of conversation is their long-time resentment over domination by governments, armies, and bureaucracies coming from the Punjab region.