Two blasts were heard near Erbil's airport, which hosts advisers from the US-led anti-ISIS coalition, in Iraq's northern Kurdistan region, an AFP journalist said on Monday.
Some hours earlier, air defense systems downed four missiles headed towards the US consulate in Erbil, a security source told AFP.
Local authorities also reported a separate deadly drone incident in a civilian area in the early hours of Tuesday morning.
The autonomous region's Counter-Terrorism Service said a "bomb-laden drone coming from Iran" crashed into a home in the Dara Shakran subdistrict of Erbil province after midnight, killing a couple.
Since the Middle East war erupted on February 28, shadowy Iraq-based groups have been claiming near daily attacks on US interests in the country and beyond.
The groups are nominally part of the "Islamic Resistance in Iraq", a loose alliance of pro-Iran factions opposed to the US presence in the country.
These groups have in turn come under attacks blamed on the United States and Israel.
Efforts to restore calm
Amid the tensions, media and political sources within the pro-Iran ruling Coordination Framework have spoken of efforts by head of the Badr organization Hadi al-Ameri to stop the escalation between the armed factions and Washington.
An official source in the Framework told Asharq Al-Awsat that it was unlikely that Ameri or others would be able to reach an agreement between the two parties to stop the attacks.
Speaking on condition of anonymity, the source said the situation inside the Framework is "in disarray" and the conditions on the ground are complicated, so achieving de-escalation is "very difficult", noting that previous efforts to restore calm had failed.
The majority of Framework leaders are operating independently from each other because they are pursuing their own interests and seeking their own survival. Some are approaching the US and others Iran, added the source.
All of these actions are driven by post-war interests, it explained.
The source stressed that Iran is the only party capable of controlling the armed factions, whether in ordering them to continue to the attacks or stop them.
So, all other efforts, including the ones by the government, will fail, he said.
Threats
Meanwhile, head of the Kataib Hezbollah in Iraq Abu Hussein al-Hamidawi warned in a statement on Monday that the Hormuz Strait "will not be opened to enemies."
In a statement, he said: "Any attempt to open the strait by force will lead to the disappearance of oil or gas platforms" - a possible threat to attacks on platforms in the Gulf.
"They must realize that either everyone or no one is safe," he went on to say.
He also said that the "Syrian front has now entered our defensive war and it will have a grievous impact on the enemies." He did not elaborate.
The Harakat al-Nujaba threatened to attack energy interests, bases and stations tied to the US at dawn on Tuesday, saying they were all "legitimate targets for the resistance."
"There are no red lines in this confrontation," said the group's military aide.
‘Egregious attacks’
The Pentagon has acknowledged that helicopters have carried out strikes against pro-Iran armed groups in Iraq during the war.
On Sunday, the US embassy in Baghdad said: "Iraqi terrorist militias affiliated with Iran conducted two more egregious attacks against US diplomatic facilities in Iraq overnight in an attempt to kill American diplomats."
The embassy spokesperson urged Iraqi authorities to prevent further attacks on the US mission and facilities.
"We will not hesitate to defend our personnel and facilities should the Iraqi government be unable to fulfill its obligations," the spokesperson said.
On Thursday, the Iraqi foreign ministry said it was "exerting maximum effort to prevent any escalation", including strengthening security to protect foreign and diplomatic interests as well as maintaining internal stability.
The Kurdistan region's Peshmerga security forces have also faced multiple attacks since the start of the war, with six of their fighters killed in an Iranian attack in March.
On Monday, the Peshmerga ministry said its command headquarters was attacked overnight by four explosive-laden drones, without specifying whether there were any casualties.
"Until now, there has not been a serious stance or practical steps to deter these terrorist attacks and put an end to them" by Iraq's federal authorities, the ministry said.
