Former brigadier general Mohammed Hamo, 65, who lives in Sweden, is accused of "aiding and abetting" war crimes. If convicted, he could get a life sentence.

The Stockholm district court is expected to announce its verdict at 11:00 am (0900 GMT).

The war between President Bashar al-Assad's regime and armed opposition groups, including Islamic State, erupted after the government repressed peaceful pro-democracy protests in 2011.

It has killed more than half a million people, displaced millions, and ravaged Syria's economy and infrastructure.

According to the charges, Hamo contributed -- through "advice and action" -- to the Syrian army's warfare, which "systematically included attacks carried out in violation of the principles of distinction, caution and proportionality".

"The warfare was thus indiscriminate," prosecutor Karolina Wieslander told the court when the trial opened in April.

Wieslander said the Syrian army's "widespread air and ground attacks" caused damage "at a scale that was disproportionate in view of the concrete and immediate general military advantages that could be expected to be achieved".

In his role as brigadier general and head of an armament division, Hamo allegedly helped coordinate the supply of arms and ammunition to units.

Hamo's lawyer, Mari Kilman, told the court her client denied criminal responsibility and had not shown "intent" to contribute to "indiscriminate warfare" by others.

Kilman said the officer could not be held liable for the actions "as he had acted in a military context and had to follow orders."

- First of its kind -

Aida Samani, senior legal advisor at rights group Civil Rights Defenders -- which has been monitoring the trial -- told AFP that "strong evidence" had been presented at the trial.

"We will now see what the court makes of that information and evidence," Samani said.

"What is noteworthy about this case is that this is the first trial concerning the Syrian military's warfare. That is, how the warfare was carried out," she said.

No European court has previously dealt with this issue and the impact on civilian lives and infrastructure, she added.

Hamo is the highest-ranking military official to go on trial in Europe in person, though other countries have tried to bring charges against more senior members.

In March, Swiss prosecutors charged Rifaat al-Assad, an uncle of President Bashar al-Assad, with war crimes and crimes against humanity.

However, it remains unlikely Rifaat al-Assad -- who recently returned to Syria after 37 years in exile -- will show up for the trial, for which a date has yet to be set.

Swiss law allows for trials in absentia under certain conditions.

In November, France issued an international arrest warrant for Bashar al-Assad, accusing him of complicity in crimes against humanity and war crimes over chemical attacks in 2013.

Three other international warrants were also issued for the arrests of Bashar al-Assad's brother Maher, the de-facto chief of the army's elite Fourth Division, and two generals.

In May, a Paris court also ordered life prison sentences for three top Syrian security officials for complicity in crimes against humanity and war crimes.

The accused -- Ali Mamlouk, former head of the National Security Bureau; Jamil Hassan, former director of the Air Force intelligence service; and Abdel Salam Mahmoud, former head of investigations -- were all absent, but there are international warrants for their arrest.

In January 2022, a German court sentenced former colonel Anwar Raslan to life in jail for crimes against humanity. That was the first international trial over state-sponsored torture in Syria and was hailed by victims as a victory for justice.