What you need to know: The latest developments on Syria

What you need to know: The latest developments on Syria
In this image taken from video obtained from the Shaam News Network Thursday, Aug. 29, 2013, which has been authenticated based on its contents and other AP reporting, members of the UN investigation team take samples from the ground in the Damascus countryside of Zamalka, Syria. (AP Photo/Shaam News Network via AP video)

United Nations experts are investigating the alleged use of chemical weapons in Syria as the United States prepares for the possibility of a punitive strike against President Bashar Assad's regime, blamed by the Syrian opposition for the attack.

The international aid group Doctors Without Borders says at least 355 people were killed in the Aug. 21 attack in a suburb of Damascus, the Syrian capital.

Here's a look at key Syria developments around the world Friday amid heightened tensions over potential military action:

FRANCE:

French President Francois Hollande said his country can go ahead with plans to strike Syria for allegedly using chemical weapons despite the British parliament's failure to endorse military action. He told the newspaper Le Monde that the "chemical massacre of Damascus cannot and must not remain unpunished."

SYRIA:

U.N. experts began what is expected to be the last day of their investigation into the Aug. 21 attack. After an early morning delay, three U.N. vehicles left a Damascus hotel for more on-site visits. It was not immediately known where they were going.

RUSSIA:

Presidential foreign policy advisor Yuri Ushakov expressed puzzlement over why the U.N. team was leaving so soon "when there are many questions about a possible use of chemical weapons in other areas in Syria." He said Russia has not seen the U.S. intelligence that Washington claims proves the role of the Syrian government in last week's alleged chemical weapons attack.

BRITAIN:

Treasury chief George Osborne warned that Britain should not turn its back on the world after the stunning parliamentary defeat of a government motion for military intervention in Syria. He told the BBC there will be "national soul-searching" about Britain's global role after the "no" vote.

UNITED STATES:

U.S. Defense Secretary Chuck Hagel defended the principles behind the planned strike. Speaking from Manila, Philippines, he said Washington would continue to seek partners in its Syria mission: "Our approach is to continue to find an international coalition that will act together."

GERMANY:

German government spokesman Steffen Seibert said Germany isn't considering joining military action against Syria and hasn't been asked by others to do so. Berlin has called for the international community to take a "clear position" following the alleged chemical attack, but has left open what exactly that might entail.

IRAQ:

Followers of anti-American Shiite cleric Muqtada al-Sadr held rallies in Baghdad and the southern Iraqi city of Basra to denounce any Western strikes against Syria. In the capital, about 2,000 Sadrists demonstrated while chanting anti-American slogans after Friday prayers. About 3,000 Sadrists rallied in Basra, some carrying banners reading "No to America."