- Mika Yammoto is the latest journalist to be killed in the Syrian civil war
- Two journalists working for the U.S.-based Alhurra TV are missing
- Obama issues a stern warning to al-Assad
(CNN) -- The gruesome civil war in Syria that pits government forces against rebels is now in its 17th month. Here are the latest key developments:
On the ground: 1 journalist killed, 2 missing
The Syrian regime severely restricts access to foreign journalists -- and those who do manage to enter the country risk detention or even death.
A Japanese journalist was the latest to pay the ultimate price when she was killed Monday during a gun battle in Aleppo, Syria's largest city and commercial hub.
Mika Yammoto, who worked for the independent Japan Press news agency, was reporting on the rebel Free Syrian Army, the Japanese foreign ministry said.
"I have seen the news on the television. I really did not want to believe it," her father Koji Yamamoto said Tuesday. "She always thought of children and women under the fire of conflict and kept saying it's her mandate to tell the stories of those people to the world."
At least 19 other journalists have so far been killed while covering the conflict, says the nonprofit group, Committee to Protect Journalists.
In Monday's incident, two other journalists are missing, and may have been arrested by the Syrian army. They work for Alhurra TV, a U.S.-based station.
"A Japanese female journalist was killed by the regime forces, who also attacked (an) Alhurra TV crew and captured the reporter and his Turkish cameraman," a man identified as Capt. Ahmed Ghazala of the Free Syrian Army said in an amateur video that Alhurra aired.
World reaction: Do not cross the 'red line,' Obama warns
U.S. President Barack Obama has delivered a stern warning to President Bashar al-Assad: Use chemical weapons, and risk provoking a military response.
"We have communicated in no uncertain terms with every player in the region that that's a red line for us and that there would be enormous consequences if we start seeing movement on the chemical weapons front or the use of chemical weapons," Obama said Monday.
Syria is a juggernaut when it comes to chemical weapons, analysts say.
The regime "probably has the largest and most advanced chemical warfare program in the Arab world," Michael Eisenstadt of the Washington Institute for Near East Policy told CNN last month.
It includes thousands of rocket artillery rounds filled with mustard-type blister agents that can damage skin and lungs, and bombs filled with sarin that attacks the nervous system.
Syria had always denied it owned any chemical or biological weapons. But the denial ended last week when Foreign Ministry spokesman Jihad Makdissi issued a peculiarly veiled threat.
"No chemical or biological weapons will ever be used," Makdissi said before flashing the thunderbolt of an exception: "Unless Syria is exposed to external aggression."
Al-Assad has long described the uprising against his rule as a terrorist revolt and a "foreign conspiracy."
CNN's Yousuf Basil and Junko Ogura contributed to this report.
