Washington already has warned shipping companies that "Iran or its proxies" could be targeting maritime traffic in the Persian Gulf region and said it deployed an aircraft carrier strike group and B-52 bombers there to counter the threat.
Iranian Foreign Minister Mohammad Zarif, speaking in Tokyo on Thursday, said Iran was committed to an global nuclear deal but the escalating USA sanctions were "unacceptable".
Later, Zarif told reporters there was "no possibility" of negotiations with the United States to reduce spiralling tensions, describing USA pressure as an "act of suicide". In other comments carried on the semi-official Mehr news agency, Zarif was quoted as saying "a multilateral deal can not be treated unilaterally".
The attack "proves that these militias are merely a tool that Iran's regime uses to implement its expansionist agenda", tweeted Prince Khalid bin Salman, a son of King Salman.
Iran has been accused by the USA and the United Nations of supplying ballistic missile technology and arms to the Houthis, which Tehran denies.
Fawaz Ahmed, a middle-aged broker, told The Associated Press he saw the three bodies being retrieved from the rubble - a father, his child and his wife, all buried together.
Meanwhile, Saudi Arabia-led military coalition carried out air strikes on the Yemeni capital on Thursday. The drone attacks on the pipeline marked one of the rebels' deepest and most significant strikes inside Saudi territory since the conflict began.
This statement came out hours after Houthi-owned TV Almasirah reported that "7 Drones have targeted vital Saudi facilities".
Tensions have been rising in the Gulf since the USA stopped granting waivers to buyers of Iranian oil and slapped crippling sanctions on the Islamic Republic after President Donald Trump pulled the USA out of the landmark 2015 nuclear deal.
Iran "does not seek clashes in the region", Zarif said in an interview with Iranian state television during his Japan trip, "but it has always defended its interests forcefully and will continue to do so now".
On Wednesday, the US State Department ordered all nonessential government staff to leave Iraq, and Germany and the Netherlands both suspended their military assistance programs in the country in the latest sign of tensions. Iraq is home to powerful pro-Iranian militias, while also hosting more than 5,000 American troops. The US military's Central Command said its troops were on high alert, without elaborating.
Washington says it has received intelligence on possible attacks by Iranian or Iranian-backed forces, possibly targeting U.S. bases in Iraq or Syria. His comments exposed worldwide skepticism over the United States military buildup.
Iranian foreign minister Javed Zarif had held talks with external affairs minister Sushma Swaraj in New Delhi on Monday as part of his diplomatic drive to talk to shareholders about the recent developments and Iran's steps to suspend commitments under nuclear deal.
The attacks took place against a backdrop of U.S.
Though Iran maintains its nuclear program is for peaceful purposes, scientists say the time needed to reach the 90 per cent threshold for weapons-grade uranium is halved once uranium is enriched to around 20 per cent.
Late Wednesday, Anwar Gargash, the UAE minister of foreign affairs, said the Saudi-led coalition would "retaliate hard" for attacks on civilian targets, without elaborating.
On Sunday morning, reports emerged that four ships "were subjected to sabotage operations" off the UAE coast of the northern emirate of Fujairah. -Iranian tension following Washington's decision this month to try to cut Tehran's oil exports to zero and beef up its military presence in the Gulf in response to what it called Iranian threats. The other ships were a Norwegian-registered oil products tanker and a UAE-flagged bunker barge.