FORWARD OPERATING BASE TILLMAN, Afghanistan — Insurgents attacked four American outposts simultaneously near the border with Pakistan on Friday, striking the positions with multiple rockets and, at one base, a suicide bomber who exploded his vehicle near one of the base’s walls.

Second Platoon, Bravo Battery, 1st Battalion, 77th Field Artillery Regiment fired a 105mm artillery barrage toward a insurgent rocket position beside the Pakistan border. (Tyler Hicks/The New York Times) The coordinated attack, apparently timed to mark the 10th anniversary of the start of the Afghan war, caused minimal damage and wounded only one American soldier, whose injuries, officers said, were not life-threatening.

But it underscored the frustrating complexities of a war entering its second decade. Most of the high-explosive 107-millimeter rockets striking the outposts were fired from just inside Afghanistan, suggesting that the attack had been prepared and launched from Pakistan, and the rocket crews withdrew there as the Americans fired back.

It also highlighted the relative weakness of Afghan soldiers and police officers living and working on the American-built bases. As the attacks escalated in the morning, only the United States military possessed the firepower, communications and skills to fight back in what developed into a long-range, artillery-and-rocket duel.

While the American soldiers organized and coordinated their part of the battle on the outpost here, the Afghan soldiers did not participate. Some simply sat and watched.

The first rocket landed near Forward Operating Base Tillman shortly after 6 a.m., shaking the ground and beginning the war’s anniversary with a crunching roar. It had been fired a few hundred meters from the border, on the Afghan side, soldiers said. It wounded no one, but hinted at what the day would bring.

More rockets followed, including one that narrowly missed the base entrance. About 9:35 a.m., another rocket hurtled toward the base.

“Incoming!” one of the soldiers shouted, as others flinched and waited for the blast. The rocket sailed overhead and struck an Afghan home.

“Hit the town,” a soldier said, flatly, at his post in the operations room.

“Killing their own people,” another answered.

Soon Afghans emerged from the compound. No one had been hurt.

By that time, rockets were falling on three other bases as well — Forward Operating Base Orgun-e, Forward Operating Base Boris and Combat Outpost Margah, Capt. William P. Hoffman said. The outpost at Margah was hardest hit.

Dozens of 107-millimeter rockets struck on or near the post, officers said, and as the attack escalated, a man drove a vehicle toward the base walls and detonated it. The base was also hit with small arms fire, officers said.

The soldiers prepared to repel a ground attack to try to breach the walls, but with American artillery and aircraft firing, any raid was thwarted, the soldiers said.

More rockets, meanwhile, struck Forward Operating Base Tillman, prompting the soldiers to return fire with 105-millimeter howitzers.

After the barrage, a fresh rumbling could be heard. It was thunder. Rain began to fall. “That’s good,” said Henry E. Pettigrew, 25, a gunnery sergeant. “Now they won’t fire anymore.”

Rocket crews from the Taliban or the Pakistan-based Haqqani network, Sergeant Pettigrew and other soldiers said, typically stop firing when it rains, perhaps because their makeshift launchers do not work as well when the soil is wet and slick.

After lunch, the sky briefly cleared, and the firing resumed. A rocket slammed to earth beside the base. Sirens wailed anew.

At the gun line, the soldiers in the howitzer platoon loaded their tubes again and returned fire with 18 rounds.

At that point, the platoon had fired more than any day since arriving in Afghanistan in the summer — 142 in all, half of them air-bursting high-explosive rounds and half white phosphorus with so-called point-detonating fuses, which cause the rounds to explode upon striking the ground.

White phosphorus is not forbidden in Afghanistan, though American and NATO rules restrict its use only to when its burning effects are deemed necessary and cannot be replicated by other munitions.

In this case, soldiers said, the white phosphorus rounds were intended to burn any Taliban rockets at the firing positions, to prevent their being fired on the American outposts.

The battle had settled into a duel that appeared familiar to both sides, facing each other near the border, exchanging long-range fire. The insurgents would fire first, and the Americans would reply.

One noncommissioned officer pulled aside a reporter and vented about the origins of the attacks.

“You know where it all comes from,” he said, and nodded toward a nearby ridge. “Pakistan.”

He swore, and went back to the business of making sure the return barrages landed within the Afghan side. He asked that his name be withheld.