Explosion rock Syria bases for Iran-backed militias day after US-led strikes

Explosions have reportedly rocked areas near Syrian military bases where pro-regime Iranian fighters and allied Shia militias have been stationed.

Opposition activist Mustafa Abu Mohammad told The New Arab late on Saturday that the sound of a massive blast was heard in southern Aleppo province.

"The source of the blast was Jabal Azzan, where Iranian and Hizballah forces have a military base," the activist said.

He added that the origin of the blast was not immediately clear and could have been caused by an airstrike or an incident at an ammunition depot.

The Syrian Observatory for Human Rights has also reported that an explosion has occurred at the site.

Al Jazeera has reported that air strikes carried out by unknown forces have hit four regime-held positions in the eastern province of Deir az-Zour.

Hizballah has denied reports that the locations were hit by Israeli air raids.

Western powers carried out their biggest attack on Assad's regime before dawn on Saturday with strikes on targets they said were linked to Syria's chemical weapons programme.

The Pentagon subsequently said no further strikes were planned as part of an operation launched a week after a suspected chemical attack on the holdout rebel town of Douma killed at least 40 people.

Israel, which was not involved in Saturday's unprecedented wave of missile strikes but expressed full support, has unilaterally launched air raids on targets inside Syria.

Russia and the Syrian military have blamed Israel for a pre-dawn missile attack on Monday which came hours after the suspected regime chemical attack.

At least 14 fighters, including Iranians, were killed in the strike on the T-4 airbase in Homs province.

Israel acknowledges carrying out dozens of airstrikes in Syria to stop what it says are advanced arms deliveries to its enemy Hizballah, the Lebanese militant group, which is backing the Assad regime along with Iran and Russia.