US soldiers in a Bradley Fighting Vehicle (BFV) patrol the countryside of al-Malikiya town in Syria's northeastern Hasakeh province, July 17, 2023. (PHOTO / AFP)

DAMASCUS/TEHRAN/BAGHDAD/SANAA - At least nine militants were killed in after-midnight US airstrikes on military sites in Syria's eastern province of Deir al-Zour, a war monitor reported Thursday.

According to the Syrian Observatory for Human Rights war monitor, US warplanes hit military sites and a weapons depot after midnight Thursday in the vicinity of Bor Saeed Street, east of the city of Deir al-Zour. 

On Wednesday, an Iraqi Shi’ite militia claimed responsibility for rocket and drone attacks on a US military base in al-Shaddadi in northeastern Syria

The strikes have killed at least nine militants, the monitor said, adding that the death toll will rise because of the number of critically wounded fighters.

The Pentagon confirmed that it was a US-led airstrike in Deir al-Zour, saying in a statement that the US military conducted "self-defense airstrikes" on a facility in eastern Syria in response to attacks against US personnel in Iraq and Syria by Iranian-backed IRGC-Quds Force affiliates.

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Meanwhile, Syria's pro-government Sham FM radio reported powerful explosions at the al-Omar oil field, where a US base is located, in the eastern countryside of Deir al-Zour.

Earlier on Wednesday, an Iraqi Shi’ite militia claimed responsibility for rocket and drone attacks on a US military base in al-Shaddadi in northeastern Syria.

An armed group calling itself the "Islamic Resistance in Iraq," which is an umbrella body for Iranian-backed Iraqi militias, claimed in two separate online statements that its fighters had launched booby-trapped drones and rockets toward a US base in al-Shaddadi and the drones and rockets had hit their targets, without giving further details.

READ MORE: Iraqi Shi'ite militia claims attacks on US bases in Syria, Iraq

The Syrian Observatory for Human Rights confirmed that the al-Shaddadi base was attacked twice and US anti-aircraft weapons shot down two drones in one of the attacks.

The incident marks the 26th recorded attack on US bases in Syria since Oct 19. Casualties have not yet been reported.

The current incidents seemed to be as part of the recently escalating exchange of fire between pro-Iran fighters and the US forces in Deir al-Zour, reports said.

The escalation comes on the heels of the Israeli-Hamas conflict in the Gaza Strip, as pro-Iran fighters in Syria deem the United States responsible for the escalation in Gaza, according to the reports.

Amir Saeid Iravani, Iran's ambassador and permanent representative to the United Nations, addresses the UN General Assembly, on Feb 23, 2023, at UN headquarters. (PHOTO / AP)

Iran denies involvement

Iran denied involvement in the attacks on US forces in Syria and Iraq.

Earlier on Tuesday, the Iranian envoy to the United Nations (UN) said Iran "has never been involved in any attack or action against US forces in Syria and Iraq," according to the official news agency IRNA.

The Iranian envoy to the UN stressed that Iran's presence in Syria was "completely legal" and in response to the Syrian government's official request to be provided with support in its fight against terrorism

Amir Saeid Iravani, Iran's ambassador and permanent representative to the UN, made the remarks in a letter addressed to UN Secretary-General Antonio Guterres.

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He rejected as "baseless claims" the accusation made by the United States in a letter to the UN Security Council in late October.

In a letter to the UN Security Council on Oct 30, Linda Thomas-Greenfield, US representative to the UN, said her country's forces carried out strikes on two facilities in eastern Syria "in response to the ongoing attacks on American personnel in Iraq and Syria," for some of which she blamed groups affiliated to Iran.

She added that the US strikes were made as part of the country's right to self-defense under the UN Charter's Article 51. 

Iravani argued that the US allegations, based on an "arbitrary and incorrect" reading of a UN Charter article, failed to have any legal basis and validity.

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He said based on international law, "an occupying state is not entitled to resort to the right of self-defense as a valid justification for its unlawful actions within the occupied territory."

"The US remarks were aimed at whitewashing its illegal military presence and actions in Syria, including targeting civilians and critical infrastructure," he claimed.

He stressed that Iran's presence in Syria was "completely legal" and in response to the Syrian government's official request to be provided with support in its fight against terrorism.

More Israeli airstrikes

Israeli airstrikes hit military positions in southern Syria on Wednesday night, causing material damage, the Syrian Defense Ministry said in a statement.

The Israeli forces carried out the strikes from the direction of Lebanon's Baalbek city at approximately 22:22 local time (1922 GMT), targeting several military installations in the southern region, according to the statement.

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While the statement did not identify the targeted sites, the Sham FM radio said the Israeli attacks hit positions in the vicinity of the capital Damascus and in the southern province of Sweida.

A military outpost in southern Syria is seen on Oct 22, 2018. (PHOTO / AP)

Meanwhile, the Syrian Observatory for Human Rights also reported multiple explosions resulting from Israeli strikes on the outskirts of Damascus.

The Israeli shelling targeted Aqraba's farms in the countryside of Damascus, where a military air base is located, just 13 km west of the international airport of Damascus.

In Yemen, Houthi militia on Wednesday said it shot down a US drone in the Red Sea

The attacks also hit a radar station southwest of Damascus, the observatory added.

The Syrian air defenses were triggered and have attempted to thwart the Israeli attacks, according to the UK-based watchdog group.

READ MORE: Tehran: Attacks on US bases in Iraq, Syria not related to Iran

The group has counted 15 instances of Israeli attacks on Syrian territory between Oct 10 and Oct 30, among which 10 were airstrikes and five were missile attacks.

US drone shot down

In Yemen, Houthi militia on Wednesday said it shot down a US drone in the Red Sea.

"Our air defenses shot down a US MQ-9 drone, which was conducting hostile activities in Yemeni airspace," Houthi military spokesman Yehya Sarea said in a statement aired by the group's al-Masirah TV.

"Hostile activities will not prevent us from continuing to carry out military operations against Israeli targets," Sarea added.

On Monday, the Houthis, who control much of northern Yemen, said they launched a batch of bomb-laden drones toward Israel, targeting what they claimed "sensitive targets," including military bases and airports.

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The attack was the fifth military operation claimed by the militia against Israel since the latter's new round of conflict with Hamas.

Last month, the US said its navy in the northern part of the Red Sea intercepted several drones and missiles fired by the Houthis in Yemen toward Israel.

As part of the Iran-backed "Axis of Resistance," the Houthis have rallied behind the Palestinians since Hamas launched a surprise attack on Israel early last month.