The US occupation on Thursday waged aggression on civilian sites in Deir Ezzor from an occupied area in Al-Tanf, a senior Iranian advisor said Friday.

"The targets that were hit are food stores and service centers," the advisor told the UNews news website. "This aggression left seven martyrs and injures seven other innocents who did nothing wrong except for serving the locals, their people, in the area."

"We are fully aware that the US occupation is trying to cause injuries among our ranks under false pretexts that it has long used to justify its criminality," he added. "Based on that, we underline that our mission, through our legitimate presence in Syria, has been to help the Syrian state to confront the terrorists and the takfiri project led by ISIS."

"For years, the region has been under attack from the American occupation, in an attempt to impose an equation of force, and their pretext has always been that they are returning fire. In the end, it turned out that they are seeking to attack precision weapons and systems that Iran is transporting, which pose a threat to their protégé, Israel," the top Iranian advisor said.

The Iranian defense official threatened that in light of the attack launched from the US-occupied Syrian region of Al-Tanf by the Americans, "we warn the US enemy that we have the upper hand, and we are able to respond in the event that our sites and forces are targeted on Syrian soil."

The statements come after the US military said it carried out "precision airstrikes" in eastern Syria on Thursday in response to an alleged drone attack that killed one American and injured five US service personnel.

The US military controls parts of the provinces of Al-Hasakah, Raqqa, Aleppo, and Deir Ezzor, where the largest Syrian oil and gas fields are located. The Syrian government has repeatedly called the US military presence in the provinces an occupation aimed at plundering the country's oil.

Read next: US occupation bases under fire in Syria for second day in a row

A Department of Defense statement claimed that the casualties fell "after a one-way unmanned aerial vehicle struck a maintenance facility on a Coalition base near Hasakah in northeast Syria."

The US has for long employed the alleged "ISIS threat" as a pretext to continue its illegal occupation of northeastern Syrian territories, frequently looting oil and gas from Syrian fields and transporting them to other occupation bases in Iraq via illegal crossings.

The US shelling came after media reports said Friday that missile strikes targeted a US occupation base in the Al-Omar field, the largest oil field in Syria located in the governorate of Deir Ezzor in the country's northeast.

Two occupation soldiers injured during the attack were treated on site, while three others were evacuated to the medical facility in Iraq along with a wounded contractor, The New York Times said.

It was reported earlier in the day that armed groups fired about a dozen rockets at a US base while attacking a second base in the area, but the strike led to no casualties.