SILOPI, Turkey - The air near Turkey's border with Iraq echoed with thunder and smelled of mud and fear.
Lightning flashed along the banks of the Tigris River as a thunderstorm rolled down mountain slopes. A few covered trucks splashed through lakes of mud, carrying mysterious cargoes south toward Iraq.
Silopi's hilly streets flowed yesterday like braided streams. Water rushed under cars, across cracked sidewalks and past the hooves of horses pulling rubber-tired carts.
"If anything unpleasant happens, if missiles land here, it could be very messy," said Enver Ogun, a young Silopi shopkeeper who had just taped a photocopied flier for gas masks in the window of his gift shop. "Tensions are very high."
Pedestrians paid little attention to the ad. Maybe that was just as well. Ogun said he would have to order them from an Ankara supplier. It seemed a pretty poor bet that the masks, the cheapest of which cost about $46, would arrive in time to save anyone.
The Turkish military presence here seems to grow by the day. Beefy commandos in blue berets and paramilitary police units patrolled the streets of Silopi and other towns in this predominantly Kurdish area, where post-Sept. 11 restrictions on trade with Iraq have thrown thousands out of work.
More ominously, about 100,000 Turkish troops were still waiting yesterday along the Turkey-Iraq border - for what, exactly, it was not clear.
Turkey, which recently concluded its long war against Kurdish separatists, says it wants to protect its borders and plans to dispatch some troops into Kurdish-controlled northern Iraq to prevent bloodshed. The United States, which first approved the plans, now opposes them.
Iraqi Kurds run northern Iraq as a quasi-independent state under the United States no-fly zone. Many accuse Turkey's government of threatening their autonomy and coveting northern Iraq's oil fields. And they have threatened to battle Turkish troops who penetrate too far into their territory.
It's not safe in this predominantly Kurdish area of Turkey to speculate on what the military will do, or to talk openly of the Kurds' stubborn hopes for an independent state. So people who clustered on street corners gossiped about reports that hundreds of Iraqi soldiers had surrendered in northern Iraq.
After United States and coalition aircraft struck 10 pieces of artillery in the southern no-fly zone, Turkish television reported - prematurely - that the war had begun. Some were quietly jubilant, others anxious.
"I want Saddam Hussein to be destroyed, I want him to die," said Yilmaz Bekler, who fled here from Kirkuk in Iraq seven years ago, leaving his father and many cousins behind. "I want him to go to hell."
The former construction worker collects trash for the city of Silopi, supporting a wife and seven children on a tiny salary.
"We ran away from his cruelty, from his dictatorship," he said. "If this war succeeds, I will go home at once."
On the Iraqi side of the border before hostilities began, levels of anxiety were much higher. One man, who identified himself only as Tahir, a 35-year-old taxi driver, said his sister piled her three children in a car yesterday and started driving to Turkey from the northern Iraqi town of Zaho.
Aid officials said they had not heard reports of an exodus of refugees - yet. But now that war has begun, it is clear that, sooner or later, refugees will begin trickling, or spilling, into this region. As one aid official said, there are already "cracks in the dam."
During the Persian Gulf war 12 years ago, 500,000 Kurds headed north to escape the fighting. This time, says Francis Teoh, head of the Silopi office of the United Nations High Commissioner for Refugees, about 80,000 are expected to try to cross into Turkey. The United Nations fears that as many as 600,000 refugees might try to enter neighboring countries.
By last night, there were only about a dozen UNHCR staff here in Silopi, just a fraction of the 80 who have been assigned. Teoh was worried that his and other aid agencies should be further along with preparations.
He wanted to help the Turkish government with plans to set up 18 refugee camps, if needed. Twelve are planned for the Iraqi side of the border, and six could open inside Turkey. But he said Ankara has not yet told UNHCR where they will be located.
To equip the camps, the United Nations has stockpiled 21,000 tents, 250,000 blankets, 55,000 mattresses, 17,000 stoves, 20,000 jerry cans for water and 12 tons of soap.