Turkey deployed a convoy of about 30 military vehicles -- including antiaircraft guns and rockets -- along its border with Syria on June 28 in the latest sign of tension between the two countries.
Turkish officials called the deployment "a precaution" after a Turkish military jet was shot down by Syria on June 22 over the Mediterranean Sea.
Prime Minister Recep Tayyip Erdogan has warned that any Syrian military units moving toward the border would be deemed as threatening and would be declared a military target.
Speaking after Turkey's allies in NATO earlier this week vowed "strong solidarity" with Ankara in its confrontation with Syria, Erdogan said Turkey has changed its rules for military engagements along the border.
Erdogan said Turkey's military will no longer tolerate violations of its border by Syrian forces. He accused Syrian helicopters of crossing into Turkish airspace at least five times recently.
Syrian Fighting Continues
Syrian artillery also reportedly has fired across the border in an attempt to target rebels who have fled into Turkey along with thousands of refugees to escape the Syrian regime's crackdown on dissent.
In Damascus on June 28, an explosion near the Palace of Justice in the center of the capital was blamed by state television on "terrorists," a term used by President Bashar al-Assad to describe those who have risen up against his regime.
There also were reports of clashes between government troops and opposition fighters for a third consecutive day in the suburbs of Damascus.
The developments come as diplomats are preparing for a June 30 meeting of the United Nations Action Group on Syria, a gathering called by international envoy Kofi Annan.
An unnamed U.S. official was quoted on June 27 as saying
that world powers -- including Russia -- had endorsed a Syrian transition plan that includes a call for President Bashar al-Assad to give up power in favor of a national unity government.
Russian Foreign Minister Sergei Lavrov on June 28 denied a reported claim from the U.S. that Russia was among the world powers to have endorsed a Syrian transition plan that includes a call for Assad to give up power in favor of a national unity government.
Lavrov said Moscow is "not supporting and will not support any external meddling" in Syria.
"Outside players ought not to dictate their own recipes to the Syrians," Lavrov said. "First of all, they ought to commit themselves to influencing all the Syrian parties to stop violence, to make sure the armed groups of both sides are withdrawn from [Syrian] cities and other populated areas simultaneously under the supervision of UN observers and to have the [Syrian] opposition give up their irreconcilable demands and sit down to negotiate with the [Syrian] government according to Kofi Annan's plan. That's all the outside players are supposed to do."
Russia has previously warned it would oppose foreign moves to pressure its ally Assad to step down.
Syrian opposition groups have reiterated that they will reject any political transition plan unless it explicitly requires Assad to quit as president before a national unity government is formed.
Lavrov also said that it is a mistake to exclude Syria's ally and neighbor Iran from the Geneva meeting.
"I know that the United States is openly making statements in Washington about its categorical opposition to Iran's participation" in the Geneva talks," Lavrov said. "However, this is a demonstration of double standards. Right now we are dealing with the need to halt the bloodshed in Syria. Iran is beyond any doubt an influential player in this situation along with other regional countries. I consider its exclusion from the Geneva meeting a mistake."
Saudi Arabia, which backs Syria's rebels, also is being excluded from the Geneva talks.
Based on reporting by Reuters, AP, AFP, and dpa