U.S. troops in Jordan launched a GPS-guided rocket artillery attack into Syria for the first time on March 4, defense officials said, revealing an new facet of the American-led coalition's ground-based fight against Islamic State militants.

The rockets came from a small detachment of fewer than 100 troops deployed near Jordan’s border with Syria. They used an M142 High Mobility Artillery Rocket System, or HIMARS, which is a truck-mounted, guided-missile system with a range of up to 185 miles . Both the U.S. Army and Marine Corps operate HIMARS.

The strike was launched in support of Syrian rebels who seized an ISIS military base near the border city of al-Tanf, where the borders of Syria, Iraq and Jordan converge, according to Army Col. Steve Warren, a Defense Department spokesman in Baghdad.

The border town was held by ISIS since May 2015 and provided a key link between ISIS territories in Syria and Iraq and an alternative to the Euphrates Valley, where U.S. and Iraqi forces are gaining ground.

Those rebels crossed into Syria from Jordan, according to the Syrian Observatory for Human Rights, a Britain-based war monitor.

The HIMARS detachment was deployed to Jordan for the first time during the past several months, Warren said.

U.S. troops last year deployed HIMARS guided missiles to Iraq, specifically al Assad air base and al Taqaddum air base in Anbar province, and have fired several hundred missiles on ISIS targets in Iraq. Yet the March 4 strike marked the first time those weapons were launched from Jordan onto targets inside Syria, Warren said.

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Virtually all other U.S. strikes on ISIS in Syria come from manned and unmanned aircraft, but Warren said there was no particular reason for the use of land-based artillery for the March 4 strike.

"That's what the weaponeers decide. There wasn't a big strategic reason or anything, it was just the system available. You know, that weapon system worked for that target set," Warren said at a press briefing Friday.

The location near Palmyra, not far from the Syria capital Damascus, suggests it was within range of the Syrian regime's formidable air defense system.

Yet Warren said the decision to use the HIMARS "had nothing to do with air defenses, nothing to do with any opposition situation. It was simply 'Hey, we've got this system, it's right here. We can use our aircraft somewhere else where the HIMARS can't reach.' So it was simply a practical decision."

U.S. aid to Jordan has increased in recent years, topping $1 billion for the first time in 2014 when the Islamic State advanced across Iraq, according to the Congressional Research Service.