Heyder Rajab, an emissary from Kurdish authorities, carried a letter recently to the Arab residents of Kapran, a rural hamlet near here: "Surrender," the letter said. "We have no quarrel with you. You can remain in your homes and on your land."

His visit was prearranged with a village elder. But Rajab didn't count on the appearance of a man named Wadi, a regional official of Iraqi President Saddam Hussein's Baath Party.

Wadi captured Rajab, interrogated him about the location of Kurdish guerrilla forces and shot him in the forehead. Villagers tossed his body on the road through a no-man's land that leads from government-held territory to Kurdish lines. The story, told by the Kurds who sent Rajab on his mission and Kurdish and Arab residents from Kapran, marked a violent episode in a tense and delicate effort by the advancing Kurds to pacify Arab villages.

The Kurds, backed by U.S. warplanes, are moving slowly toward Mosul, the largest city in northern Iraq, and Kirkuk, hub of an oil-rich region. As Iraqi soldiers retreat, the Kurds have begun to absorb villages in their area of control. Some of the villages were established by the central government in Baghdad and settled with outsiders, many of them Arabs, on land the Kurds consider their own. Others, including Kapran, have existed from time out of memory.

In all cases, the arrival of the Kurds in these Arab villages has created fear on several levels. Iraqi officials are intent on slowing further the snail pace of the Kurdish advance.

The killing of Rajab was an attempt by the Iraqis to keep the Arabs from giving in to the Kurds. "We have stopped sending go-betweens," said Adel Bakr Hamed, a Kurdish guerrilla commander. "It is too dangerous." Bakr Hamed had sent Rajab, his cousin, to Kapran.

This land has changed hands several times during decades of Kurdish revolts and subsequent government counterattacks. The Kurds have warned Arabs who were settled here by the Hussein government that they must leave. Several such "settler" villages in abandoned Iraqi territory stand empty. At the same time, the Kurds are trying to reassure long-established Arabs that they do not have to flee their villages. Some Arabs have already fled to escape death or injury from U.S. bombing.

With an undercurrent of ethnic conflict, the slow-motion war in the north has a nature almost entirely different from that of the much heavier battle in the south. Over the past three decades, Hussein expelled tens of thousands of Kurds from villages and towns. The Kurds are eager to reclaim land and homes. In particular, they consider Kirkuk a spiritual, economic and strategic capital.

With the issue of possession in play, the problems encountered in Kapran are likely to multiply if Kirkuk and Mosul fall. Few Arabs are fleeing into the Kurdish zone, whose 3 million inhabitants have lived outside central government control for 12 years.

When the Kurds occupy a village, they hoist not the Iraqi flag, but a flag of one of the two parties that rule the far north: yellow for the Kurdistan Democratic Party or green for the Patriotic Union of Kurdistan.

Kurdish officials are eager to show they are not out to drive out the Arab populations who have long lived here. So they have tried to send reassuring messages to several hamlets. Rajab, 32, a father of seven children, was a casualty of the campaign.

He had made contact with Taha Mohammed Shakaka, the Kapran elder. Sheik Taha, as he is known, was supposed to guarantee Rajab's safety. "This is the tradition in these parts," said Bakr Hamed. "They have abused the tradition."

Wadi, whose last name no one here seemed to know, was an anti-smuggling security official who now heads an execution squad, the Kurds say. "We will get him," Bakr Hamed vowed.

He was speaking in the village of Abu Shiteh, which lies on rolling plains about 25 miles southeast of Irbil, on the way to the Kirkuk-Mosul road. The road appears to be a target of the U.S.-Kurdish advance. Kurdish fighters and U.S. Special Operations detachments hold a ridge overlooking the road as well as these plains. Through binoculars from a tower in Abu Shiteh, Iraqi troops and artillery can be seen three miles away. Kapran stands between Abu Shiteh and the Kirkuk-Mosul road.

Arab villages dot the adjacent fields of wheat and yellow wildflowers. Most hamlets are abandoned. Huwera, just north of Abu Shiteh, was hit by four U.S. airstrikes four days ago. The blasts left swimming pool-sized craters along the roadside and obliterated mud and straw houses on either side. Seven civilians died, Kurdish guerrillas said, and the rest of the residents fled.

"It is hard to keep the Arabs here if the bombs are dropping," said Capt. Kamal, the Kurdish commander in Abu Shiteh. The jets also hit a pair of military jeeps at the entrance of Huwera, and their mangled chassis block part of the road.

One Arab patriarch and two of his sons have stayed in Abu Shiteh. Until three days ago it was home to 100 families. "We are here to say, this is our land. I can't leave it. The pesh merga [Kurdish guerrilla force] has acted properly. I am not afraid. We believe our people will come back," said Sayeed Ahmed, a 71-year-old Arab farmer.

In this part of Iraq, costume is an identity card. Ahmed was dressed in a long white gown with a sheer white scarf placed loosely on his head. The Kurds patrolling the village wore billowy tan pants, patterned sashes and checked scarves wound tightly as turbans. Ahmed greeted visitors in a long ceremonial hall in his wattle house. The house was empty of furniture, as were all the abandoned houses in Abu Shiteh. The Arabs had taken precautions. They left only a few flocks of ducks, geese and chickens.

He said he had heard of Wadi. The Baathist was based in Kirkuk, he said. "He was in security. We stayed away from him," Ahmed said.

He evidently still feared that a turn in the war might bring Wadi or other Iraqi authorities back. He told a Washington Post photographer, "If you try to take my picture, I'll pull out my pistol and shoot you."

Recovering the traditional diplomatic tone of rural people here, he pleaded: "I'll give you the world, but not my photo."

The pesh merga had better success in persuading Arabs in the village of Khalend, a few miles to the northwest, to remain. After five days of negotiations, Kurdish guerilla forces passed through the village today on the way to the new front line near the Great Zab River. Most women and children fled soon after the war began. "They were afraid of bombing," said Faek Hamed Abdullah, a Kahlend farmer.

Like Ahmed in Abu Shiteh, the peasants of Khalend say they stayed to safeguard their fields and homes. In 1991, the last time the Kurds revolted, battles between government forces and Kurdish guerrillas raged all around. At one point Kurds overran Khalend, burned several homes, looted furniture and stole automobiles. The stumps of old mud walls have been left in place, memorials of the last war.

"Please, take a picture of these ruins" Hamed Abdullah told a photographer. "We can't leave again, and lose everything."

An old woman, with her face tattooed in the style of desert Arabs, began to chant: "This is our land. This is ours!"

No one among the gathered Arab men offered an opinion on the course of the war. A Kurdish passerby from a neighboring village urged them to speak up. "It's over. You can say what you want."

Almost in a chorus, Hamed Abdullah and the others shot back, "Our families are in Mosul."

The Kurd shuffled silently away.

Kurdish men walk through a crater left by U.S. airstrikes on the Arab village of Huwera in northern Iraq. Seven civilians died in the attacks, guerrillas said.Fighters stand guard in Abu Shiteh, where most Arab residents fled after Kurdish forces took over the village.