The World Food Program has sent supplies to Syria's commercial capital Aleppo to help tackle shortages triggered by escalating clashes between troops and rebels, the U.N. agency said on Wednesday.

The WFP "has sent food assistance for distribution to 28,000 people in Aleppo over the next few days, following reports of shortages of food, gas and electricity following weeks of violence," a statement said.

Turkey's military on Wednesday tested its tanks' speed and maneuverability during an exercise in Turkey's southeastern border near Syria, reported the Anatolia news agency.

The exercise comes after Turkey sent a convoy of tanks, weapons and ground-to-air missile batteries to the border with Syria, strengthening its defenses there as intensified on the other side of the border.

The Czech embassy in Damascus will represent U.S. interests in Syria after Poland, which had been taking on that function for the Americans after they pulled out in February, withdrew its diplomats last week.

"Following a request from the United States, the Czech Republic has agreed to represent U.S. consular interests in Syria," a Czech foreign ministry statement said Wednesday. Talks on "technical details" are underway, it added.

Syria's rebels said on Wednesday that a government-in-exile headed by a splinter group of dissidents was "stillborn" and that it did not represent the opposition's demands.

The rebels' comments came a day after exiled dissident Haytham al-Maleh, 81, said in Cairo he had been tasked by a coalition of independent dissidents to create a government-in-exile based in the Egyptian capital.

Syria's military has used fighter jets to fire on Aleppo, the country's second city, the U.N. Supervision Mission in Syria (UNSMIS) spokeswoman told Agence France Presse on Wednesday.

"Yesterday they (U.N. observers) saw firing from a fighter aircraft" on Aleppo, said Sausan Ghosheh. "They are jets."

Rebels in Syria have now set their sights on seizing intelligence branches in the country's commercial capital of Aleppo after taking three police stations there, a rebel commander told Agence France Presse on Wednesday.

The rebels seized three police stations on Tuesday: in Bab al-Nayrab, the southern district of Salhin and in Hanano. Rebel leader Ferzat Abdel Nasser called the takeovers "a small victory that is good for morale."

Iran is the "pre-eminent" state sponsor of terrorism and together with Hizbullah are pursuing increasingly destabilizing activities around the world since the 1990s, the U.S. State Department's counterterrorism coordinator, Daniel Benjamin, said Tuesday.

“Iran is and remains the preeminent state sponsor of terrorism in the world … and also, together with Hizbullah, as they pursue destabilizing activities around the globe, we are firmly committed to working with partners and allies to counter and disrupt Iranian activities,” Benjamin told journalists after a briefing on the annual "Country Reports on Terrorism."

More than 300 people, mostly civilians, were killed in the eastern Syrian province of Deir Ezzor in July, when army operations intensified, the Syrian Observatory for Human Rights said on Tuesday.

Activists recently posted videos showing gory images of bloody, mangled bodies, including women and children, and mutilated faces strewn across several city streets.

The opposition Syrian National Council said on Tuesday that it is too early to form a government in exile and that a leading dissident's announcement that he had been tasked with forming one was damaging.

"The formation of a government in exile was a hasty decision, and we wish it had not happened," SNC chief Abdel Basset Sayda told Agence France Presse. "It actually weakens the opposition."

For 16 months, Syria's two biggest cities Damascus and Aleppo were seen as safe havens from the country's bloodshed, but deadly fighting over the past two weeks is forcing people who took refuge there to flee yet again.

Displaced at least twice since fleeing the flashpoint central city of Homs in March, one family is now looking to escape Damascus and possibly return home, after the capital was engulfed in violence last week.