ULUDERE, Turkey — Syrians fear embattled President Bashar Assad is planning to attack civilian opponents and armed rebels alike with chemical and biological weapons, human rights activists said Monday after Syria declared for the first time that its army has weapons of mass destruction.
"The whole population of Syria is afraid," said Damascus-based activist Sami Ibrahim of the Syrian Network for Human Rights.
"Now the regime is using helicopters like they are water pistols, shelling daily in Damascus. At the final stages when [Mr. Assad] feels he has nothing to lose, he could use chemical weapons."
In the first acknowledgment of such weapons, the Syrian regime said it would be prepared to use them against foreign attackers, but insisted it would not use them against its own people.
"All of these types of weapons are in storage and under security and the direct supervision of the Syrian armed forces, and will never be used unless Syria is exposed to external aggression," Foreign Ministry spokesman Jihad Makdissi said in a news conference broadcast on Syrian state TV.
"No chemical or biological weapons will ever be used and, I repeat, will never be used, during the crisis in Syria no matter what the developments inside Syria."
The statement raised questions about the regime's definition of "external aggression" as it continues to blame foreign extremists and terrorists for the rebellion, which has spread across the country over the past 17 months.
Chemical weapons thought to be in the Syrian regime's possession include nerve agents as well as mustard gas and Scud missiles capable of delivering the lethal chemicals. The regime also holds a variety of advanced conventional arms, including anti-tank rockets and late-model portable anti-aircraft missiles.
Don't even think about it
In Washington, the Obama administration warned Mr. Assad not to even consider using chemical or biological weapons.
"They should not think one iota about using chemical weapons," Pentagon spokesman George Little told reporters.
"We have been very strong in our statements inside the U.S. government on the prospective use of chemical weapons, and it would be entirely unacceptable."
U.N. Secretary-General Ban Ki-moon said, "It would be reprehensible if anybody in Syria is contemplating use of such weapons of mass destruction."
Despite denials that the regime would use its weapons against its own people, Damascus-based activist Lena al-Shami of the Revolution Leadership Council said that reports this month of security forces being issued gas masks in a Damascus suburb triggered fear among residents that chemical weapons could be used against civilians.
"People are still afraid of this," she said. "We are talking about this seriously."
Volunteer doctors and medical staff are writing contingency plans in the event of a chemical attack to distribute to residents. Precautions such as duct tape and plastic sheeting are difficult to buy because more than half of the stores are closed in many areas of the city, Ms. al-Shami said.
Crossing a line
Analysts said the regime would be ostracized by its allies of it uses its chemical arsenal.
"If it reaches the point where they have to use chemical weapons — particularly in an urban area — I think they have to know that it would draw such a response from the Arab world, the Muslim world and the international community, and I think that would be the end of any attempt by Russia and China to stand by them," said Paul Salem, director of the Carnegie Middle East Center in Beirut.
"That would be crossing a huge line, and I can't imagine that they would be that stupid," he said.
Meanwhile, Israel said that it has not ruled out military intervention to prevent chemical weapons from reaching the hands of the Jewish state's enemies.
Analysts said they thought it unlikely that Israel would get involved in a conflict that could ignite a war throughout the region.
"The United States has been trying to dissuade Israel from taking any action against Syria's chemical weapons," said Fawaz Gerges, director of the Middle East Center at the London School of Economics. "Israel will refrain from involvement because it's not in its interest to do anything."
He added that Israel is unlikely to take action unless such weapons are deployed.
Fighting in Syria's capital, Damascus, and its second city, Aleppo, has escalated since Wednesday, when four top-level regime figures, including Mr. Assad's brother-in-law Assef Shawkat, were killed when a bomb exploded in a government building during a meeting of the government Cabinet.
Clashes broke out in Aleppo over the weekend when opposition forces attempted to take the city as a base for the rebellion. In the capital, fighting was reported Monday in the district of Qadam and the outskirts of Kfar Sousa.
Analysts are conflicted over whether the intensified violence signals the end of the regime. Some said that Mr. Assad and his supporters could withdraw to Latakia in the Alawite heartland and set up an enclave that could last for decades.
"What might happen is that if the regime continues to crumble and fall, the whole regime might gradually pull back to the northwest of the country, and they could plan to take those weapons with them and hunker down there, where they would be pretty impregnable. They would lose the regime, but they would still have a zone that they could repair to," said Mr. Salem in Beirut.
Arab League leaders Monday offered Mr. Assad, his wife and three children "safe exit" if he chooses to flee Syria.
"This request comes from all the Arab states: Step aside," said Qatari Prime Minister Hamad bin Jassim Al Thani, who hosted a meeting of Arab foreign ministers.
Others said that, despite the setbacks, the continuing blows might not be fatal to the regime or its leader.
"The regime has been dealt a devastating psychological blow, and we shall wait and see if they can really adjust and absorb the shock. It could prove to be a tipping point, but I'm not convinced," said Mr. Gerges in London.
• Louise Osborne contributed from Berlin.