The US military on Tuesday shot down an Iranian drone that “aggressively” approached the Abraham Lincoln aircraft carrier in the Arabian Sea, the US military said, in an incident first reported by Reuters.

The incident came as diplomats sought to arrange nuclear talks between Iran and the United States, and US President Donald Trump warned that with US warships heading toward Iran, “bad things” would probably happen if a deal could not be reached.

Oil futures prices rose more than $1 per barrel after news the drone was shot down.

The Iranian Shahed-139 drone was flying toward the carrier “with unclear intent” and was shot down by an F-35 US fighter jet, the US military said.

“An F-35C fighter jet from Abraham Lincoln shot down the Iranian drone in self-defense and to protect the aircraft carrier and personnel on board,” said Navy Captain Tim Hawkins, a spokesperson at the US military’s Central Command.

Iran’s UN mission declined to comment.

Iran’s Tasnim news agency said connection had been lost with a drone in international waters, but the reason was unknown.

No American service members were harmed during the incident and no US equipment was damaged, he added.

The Lincoln carrier strike group is the most visible part of a US military buildup in the Middle East following a violent crackdown against anti-government demonstrations last month, the deadliest domestic unrest in Iran since its 1979 revolution.

Trump, who stopped short of carrying out threats to intervene during the crackdown, has since demanded Tehran make nuclear concessions and sent a flotilla to its coast. He said last week Iran was “seriously talking,” while Tehran’s top security official, Ali Larijani, said arrangements for negotiations were under way.

Iranian boats harass US-flagged tanker

In a separate incident on Tuesday in the Strait of Hormuz, just hours after the drone shootdown, Iran’s Islamic Revolutionary Guard Corps forces harassed a US-flagged, US-crewed merchant vessel, according to the US military.

“Two IRGC boats and an Iranian Mohajer drone approached M/V Stena Imperative at high speeds and threatened to board and seize the tanker,” Hawkins said.

Maritime risk management group Vanguard said the Iranian boats ordered the tanker to stop its engine and prepare to be boarded. Instead, the tanker sped up and continued its voyage.

Hawkins said a US Navy warship, the McFaul, was operating in the area and escorted the Stena Imperative.

“The situation de-escalated as a result, and the US-flagged tanker is proceeding safely,” Hawkins added.