An Iran-backed militia in Iraq says an explosion has occurred at a military base about 50 kilometers south of Baghdad. The cause of the blast is not known.

The Popular Mobilization Forces, or PMF, made the announcement on social media on Saturday. The militia is part of the so-called "Axis of Resistance," a network of militant groups in the Middle East.

Reuters news agency quotes two hospital sources as saying one PMF fighter was killed and six others injured.

The PMF says a team is investigating the cause of the explosion.

Analysts say the blast could further destabilize the region amid rising tensions between Israel and Iran.

US Central Command says it's aware of reports claiming that the United States conducted an airstrike in Iraq but that the reports are "not true."

CNN says both Israeli and US officials have denied any involvement in the explosion.

A number of explosions also occurred in Iran's central province of Isfahan on Friday. US media say Israel mounted the attacks in retaliation for a missile and drone strike launched by Tehran toward Israel several days earlier.