In a tragic incident, one person has been killed and at least eight others injured following a blast at a military base in Iraq that is utilized by the Iran-aligned Popular Mobilisation Forces (PMF). The explosion occurred late on Friday at the Kalsu military base, located approximately 50km (31 miles) south of Baghdad in the province of Babil.

Videos and images from the scene captured a massive explosion, which ignited fires in the surrounding areas, engulfing nearby trees. Footage from inside the base revealed significant damage to infrastructure and vehicles, with a large crater visible.

The PMF issued a statement, claiming that the Kalsu military base was bombed by "American aggression." However, the Iraqi military stated on Saturday that there were no drones or fighter jets detected in the airspace of the Babil area before or during the blast. The United States military also denied any involvement in the air strikes in Iraq.

As of Saturday afternoon, no party has claimed responsibility for the attack. The Iraqi government has launched an investigation into the incident, while Prime Minister Mohammed Shia al-Sudani is currently in the United States.

The Kalsu military base, which houses Iraqi federal police and military forces, holds an ammunition depot and a warehouse for tanks and other weaponry. It was previously under the control of US soldiers during the US-led invasion but was transferred to the Defence Ministry in 2011.

Al Jazeera's Mahmoud Abdelwahed reported from Baghdad, stating that the PMF described the attack as "indiscriminate." The victims include PMF personnel, soldiers from the Iraqi Ministry of Defense, and civilians in the vicinity at the time of the attack.

Speculations regarding the responsible party have emerged, with some accusing Israel of carrying out the attack. However, there has been no official comment from the Israeli military. Abu Fadak al-Muhammadawi, the chief of staff of the PMF, inspected the base on Saturday.

In a separate development, the Islamic Resistance in Iraq, an umbrella group opposing the US and Israel, claimed to have launched a retaliatory strike by releasing a video showing the launch of a drone aimed at a "vital target" in the Israeli port city of Eilat. This comes after a period of reduced assaults by the group since February, following the deaths of three US soldiers in a drone strike near Syria's border with Jordan.

Palestinian armed group Hamas also condemned the attack on the base, stating that it considers it a violation of Iraq's sovereignty. Expert Rich Outzen of the Atlantic Council noted that it is unlikely for the US to be involved in the attack, as it has been attempting to mediate tensions between Iran and Israel. Outzen suggested that the attack aligns more with Israel's previous actions in the region, below the threshold of direct attacks on Iran.

The incident occurs a day after Iran reported shooting down three quadcopters near a military base in the central city of Isfahan, where fighter jets and air defense batteries are stationed. Israel is suspected to be responsible for the operation, though it has not officially acknowledged it. In April, Iran launched a significant attack on Israel in retaliation for the razing of Tehran's consulate building in Syria.

As investigations into the blast at the Kalsu military base continue, the region remains on high alert as tensions between Iran and Israel persist.