A false alarm set off Syrian air defense systems early on Tuesday, the military said, denying earlier reports of an “outside aggression” and incoming airstrikes and underscoring the chaotic nature of the multiple actors in Syria’s theater of war.

Syrian state media reported hours earlier that the country confronted yet another assault, shooting down missiles over the central region of Homs and a suburb of Damascus before dawn.

The reports did not say who carried out the alleged strikes, adding to Mideast jitters only days after the United States, Britain and France conducted airstrikes targeting Syria’s alleged chemical weapons facilities in retaliation for a suspected chemical weapons attack that they blamed on the Syrian government.

The Britain-based Syrian Observatory for Human rights, which follows the war through a network of activists on the ground, reported the sound of explosions and lightning-like flashes in the skies over Homs and near Damascus, without saying what it was.

The government-run Syrian Central Media said six missiles targeted the Shayrat air base in Homs on Tuesday, adding that Syrian air defenses shot down most of them. The Syrian outlet also reported another, separate airstrike on the Dumayr air base, in a suburb of the capital, Damascus.

The Pentagon denied any American military activity in the area. There was no comment from Israel, which frequently carries out airstrikes in Syria but rarely acknowledges them.

Only hours later, Syrian TV carried a military statement saying that air defenses fired a number of missiles because of a “false alarm,” without providing more information.

Earlier this month, four Iranian military personnel were killed in an airstrike on Syria’s T4 air base, also in Homs. Syria and its main allies Iran and Russia blamed Israel for that attack. Israel did not confirm or deny mounting the raid.

The report came as experts from the international chemical weapons watchdog were in Damascus, waiting to visit the site of the suspected chemical attack in the town of Douma, just east of Damascus.

On Monday, Syrian and Russian authorities prevented investigators from the Organization for the Prohibition of Chemical Weapons from going to the scene, the head of the OPCW said, blocking international efforts to establish what happened and who was to blame.

The U.S. and France say they have evidence that poison gas was used in the April 7 attack in Douma, killing at least 40 people, and that Syrian President Bashar Assad’s military was behind it.

But they have made none of that evidence public, even after they, along with Britain, carried out airstrikes on Saturday, bombing sites they said were linked to Syria’s chemical weapons program.

Syria and its ally Russia deny any chemical attack took place, and Russian officials went even further, accusing Britain of staging a “fake” chemical attack. British Prime Minister Theresa May accused the two countries — whose forces now control the town east of Damascus — of trying to cover up evidence.

The lack of access to Douma has left unanswered questions about the attack. OPCW Director-General Ahmet Uzumcu said Syrian and Russian officials cited “pending security issues” in keeping its inspectors from reaching Douma.

“The team has not yet deployed to Douma,” Uzumcu told an executive council meeting of the OPCW in The Hague on Monday.

Instead, Syrian authorities offered them 22 people to interview as witnesses, he said, adding that he hoped “all necessary arrangements will be made … to allow the team to deploy to Douma as soon as possible.”

Russian military police were ready to help protect the OPCW experts on their visit to Douma, said Maj. Gen. Yuri Yevtushenko of the Russian military’s Reconciliation Center in Syria. Igor Kirillov, a Russian chemical weapons protection expert in The Hague, said the team is set to visit the site Wednesday.

Earlier Monday, Russian Deputy Foreign Minister Sergei Ryabkov said the inspectors could not go to the site because they needed approval from the U.N. Department for Safety and Security. He denied that Russia was hampering the mission and suggested the approval was held up because of the Western airstrikes.

However, U.N. spokesman Stephane Dujarric said the United Nations has “provided the necessary clearances for the OPCW team to go about its work in Douma. We have not denied the team any request for it to go to Douma.”

Until Saturday, Douma was the last rebel-held town near Damascus, and the target of a government offensive in February and March that killed hundreds and displaced tens of thousands.

Hours after the alleged chemical attack, the rebel faction that controlled the town, the Army of Islam, relented and was evacuated along with thousands of residents.

The Associated Press, during a government-organized visit Monday to Douma, spoke to survivors and witnesses who described being hit by gas. Several said a strange smell started spreading and people screamed, “It’s chlorine! It’s chlorine!”

The AP visited a two-room underground shelter where Khaled Mahmoud Nuseir said 47 people were killed, including his pregnant wife and two daughters, 18-month-old Qamar and 2 1/2-year-old Nour. A strange smell lingered, nine days after the attack.

Nuseir, 25, said he ran from the shelter to a nearby clinic and fainted. After he was revived, he returned to the shelter and found his wife and daughters dead, with foam coming from their mouths.

He and two other residents accused the rebel Army of Islam of carrying out the attack. As they spoke, government troops were not far away but out of earshot. Nuseir said a gas cylinder was found leaking the poison gas, adding that he didn’t think it was dropped from the air because it still looked intact.

Separately, the AP spoke to a medic who was among those who later were evacuated to northern Syria. Ahmed Abed al-Nafaa said helicopters were flying before the attack and when he reached the site, people were screaming “chlorine.” He said he tried to enter the shelter but was overcome by a strong smell of chlorine and his comrades pulled him out.

The accounts contradict what the Syrian government and Russia have reported: that there was no gas attack in Douma.

(AP)