High above Yemen's rebel-held city of Hodeida, a drone controlled by Emirati forces hovered as an SUV carrying a top Shiite Houthi rebel official turned onto a small street and stopped, waiting for another vehicle in its convoy to catch up.
Seconds later, the SUV exploded in flames, killing Saleh al-Samad, a top political figure.
The drone that fired that missile in April was not one of the many American aircraft that have been buzzing across the skies of Yemen, Iraq and Afghanistan since Sept. 11, 2001. It was Chinese.
Across the Middle East, countries locked out of purchasing U.S.-made drones due to rules over excessive civilian casualties are being wooed by Chinese arms dealers, who are world's main distributor of armed drones.
"The Chinese product now doesn't lack technology, it only lacks market share," said Song Zhongping, a Chinese military analyst and former lecturer at the People's Liberation Army Rocket Force University of Engineering. "And the United States restricting its arms exports is precisely what gives China a great opportunity."
The sales are helping expand Chinese influence across a region vital to American security interests.
"It's a hedging strategy and the Chinese will look to benefit from that," said Douglas Barrie, an airpower specialist at the International Institute for Strategic Studies. "I think the Chinese are far less liable to be swayed by concerns over civilian casualties," he said.
At the start of the year, a satellite passing over southern Saudi Arabia photographed U.S.-made surveillance drones at an airfield, alongside Chinese-manufactured armed ones.
According to the Center for the Study of the Drone at New York's Bard College, that was the first documented example of the two drone systems being used in the war in Yemen. The country has emerged as a "sort of a testing ground for these strike-capable drones," said Dan Gettinger, the co-director of the Center for the Study of the Drone. "There's a rapid turnaround from delivery to deployment."
U.S. drones were first used in Yemen to kill suspected al-Qaida militants in 2002.
One of the biggest Chinese exports is the Cai-Hong, or Rainbow, series made by the state-owned China Aerospace Science and Technology Corp., or CASC, the largest contractor for the Chinese space program.
CASC's CH-4 and CH-5 models are on a par with San Diego-based General Atomics' Predator and Reaper drones, and much cheaper. Independent analysts say the Chinese models lag behind their American counterparts but the technology is good enough to justify the price tag, which might be half or less.
A CASC executive, who spoke on condition of anonymity because he was not authorized to talk to journalists, said cutting-edge U.S. models like Boeing Co.'s Stingray, introduced this year for the U.S. Navy, still hold a technological advantage.
And while price is an advantage, so too is a more relaxed attitude toward how drones are used, said Ulrike Franke, an expert on drones and policy fellow at the European Council on Foreign Relations
Since 2014, China has sold more than 30 CH-4's to countries including Saudi Arabia and Iraq in deals worth over $700 million, according to CASC. Ten countries are currently in negotiations to purchase the CH-4, according to the firm.
Last year, China sold to the UAE the Wing Loong II, an armed unmanned aerial vehicle roughly equivalent to the American MQ-9 Reaper.
"In recent years, all types of drones have proven their value and importance through a high degree of use in warfare, and the military has noticed," said the top CASC executive. "Many countries are now speeding up the development for these weapons systems, including China."
During President Xi Jinping's five years in power, China has stepped up spending on stealth fighters and aircraft carriers for its own military, while boosting sales of advanced equipment such as attack submarines to close allies like Pakistan.
China still lags behind the U.S., Russia, France, and Germany in total arms sales but it's catching up. Chinese arms exports rose by 38 percent between 2008-12 and 2013-17, according to the Stockholm International Peace Research Institute, which tracks the global arms trade.
Mounting criticism over the rising civilian death toll in Yemen prompted the U.S. to impose restrictions on drone sales, forcing foreign countries to go through the U.S. government to buy armed drones, including those with laser-guidance systems.
The Washington-based New America Foundation estimates more than 240 drone strikes in Yemen have killed more than 1,300 people, including at least 111 civilians.
But with China's drone sales booming, there's growing pressure from U.S. arms makers to remove restrictions to let them catch up.
After some U.S. lawmakers urged President Donald Trump to loosen controls and let General Atomics sell its armed Reapers to Jordan and the UAE, the administration on April 19 permitted U.S. manufacturers to directly market and sell drones, including armed versions.
The government must still approve and license the sales, which are also contingent on human rights and proliferation reviews and congressional authorization.
General Atomics did not respond to a request for comment.
China doesn't routinely announce arms sales like the U.S. and others, but a review of drone spottings gives some indication of who its customers are.
— In Iraq in October 2015, the country's then-defense minister inspected a CH-4 drone at an air base in the city of Kut.
— Chinese armed drones have been operating at Jordan's Zarqa Airport, at an air base in Pakistan and from bases in Egypt in the Sinai Peninsula and near its border with Libya, according to satellite photos analyzed by the Center for the Study of the Drone.
— Satellite photographs taken of a mysterious air base in the United Arab Emirates' deep south — a desert area known as the Empty Quarter — appear to show three Wing Loong IIs, IHS Jane's Defense Weekly reported in January.
— Two CH-4s were spotted by satellite alongside surveillance-only Predators purchased by the UAE at Jizan Regional Airport in southern Saudi Arabia, near the kingdom's border with Yemen, according to the Center for the Study of the Drone.
— Outside of the Mideast, Nigeria has used Chinese armed drones against the Islamic extremist group Boko Haram.