Four Stryker soldiers – likely from Fort Lewis – were killed in attacks in Afghanistan on Thursday, according to several reports published Friday.

The soldiers died in the same district of Zabul province, sparsely populated and long-overlooked province along the Pakistani border. Three of the soldiers were killed when their vehicle struck a bomb, and the fourth died during a firefight with insurgents.

The Associated Press, the New York Times and the Times of London have all reported the deaths.

Members of Fort Lewis’ 5th Brigade, 2nd Infantry Division have been operating in Zabul since this summer, but the reports did not specifically name with which unit the troops served or at what installation they were based. The 5th Brigade is the only Stryker unit in the country, but special operations forces previously have used the 20-ton vehicles in Afghanistan.

Units from 5th Brigade first moved into Zabul earlier this summer to take over the Romanian-led task force struggling to keep security. Lt. Col. Karl Slaughenhaupt told Stars and Stripes newspaper earlier this month the soldiers planned on clearing villages and valleys of insurgents and then man a series of small outposts so the troops can stay close to the population they’re tasked with protecting.

“Our goal is that locals will feel more comfortable about sharing information about enemy activity, movement,” Slaughenhaupt told the newspaper. “Every indication I get from the government here is that the vast majority of the people in this province are not happy with the Taliban, [but] they have not been able to resist the enemy’s efforts to coerce them.”

But The Times newspaper reported that all schools in Zabul beyond the provincial were closed because of insurgent threats.

The Stryker units were sent in to reverse that trend.

“Zabul had been a lesser priority, and probably for good reason. There had been bigger fish to fry, so to speak, in other areas, and that has been the focus,” Slaughenhaupt told Stars and Stripes. “Now with additional combat forces, we can cover down on Zabul.”