Neighboring Turkey, meanwhile, set new rules of engagement after three shells from Syria hit Turkish territory Saturday. Turkey retaliated with artillery, as it has for the past four days, and Turkish Foreign Minister Ahmet Davutoglu said this will now be the standard response.

Davutoglu insisted that "we haven't taken a step toward war," but Turkey's threat to fire back for each errant Syrian shell was bound to keep border tensions high. Turkey is one of Assad's harshest critics and a key supporter of Syria's opposition.

The latest Syria-Turkey crisis erupted earlier this week, after a Syrian shell killed five civilians in a Turkish border town.

The Syrian regime has apologized and tried to defuse tensions by pulling some tanks back from the border, according to a Turkish Foreign Ministry official who spoke on condition of anonymity in line with government regulations.

Still, the week's daily cross-border exchanges have heightened fears of a regional conflagration.

Syrian mortar rounds are likely to hit Turkey again as regime forces try to retake rebel-controlled areas near the border. Two of the shells that fell in Turkey on Saturday were fired in clashes between government troops and opposition fighters in a Syrian border village.

Syria's civil war has been stalemated for months, but Syrian Defense Minister Gen. Fahd Jassem al-Freij insisted Saturday that the regime is gaining the upper hand.

The government denies it is facing a home-grown rebellion, saying it is being targeted by a foreign conspiracy against the regime's support for anti-Israeli groups.

"The most dangerous parts of the conspiracy have . . . passed and the killing is on its way to decline," said al-Freij, who was named to the job after his predecessor was assassinated in July. He offered amnesty to rebels who repent but said those who don't "will be crushed under the feet of our soldiers."

The Syrian president, meanwhile, made a rare public appearance Saturday to commemorate the anniversary of the outbreak of the 1973 Arab-Israeli war, also known as the October War.

Assad laid a wreath at the country's statue of the Unknown Soldier in Damascus, then passed along a line of saluting army commanders in dress uniform, shaking hands with each. The ceremony, broadcast live on Syrian TV, seemed designed to show Assad remains in control.

Syria's state-run news agency SANA linked Saturday's anniversary to the current conflict, saying that in both cases "Syria is facing an enemy armed with Western and Israeli weapons."

Along with regime's new warnings to the rebels, Syrian troops backed by warplanes and combat helicopters launched attacks on rebel-held areas near the Syrian town of Quseir, close to Lebanon's Bekaa Valley, on Saturday, Lebanese security officials said.

Opposition activists also reported intense government shelling in the northern city of Aleppo, Syria's largest and a commercial hub, and in the central city of Homs.

The battlefield stalemate is most apparent in those two cities.

Syrian forces have been bombing and shelling from a distance but have been unable to dislodge opposition fighters holed up in devastated neighborhoods. Retaking Aleppo and Homs could give the regime some breathing room.

In Aleppo, government forces gained some ground in recent house-to-house combat, according to an Associated Press journalist in the city.

On Saturday, government troops captured the city's Sakhour roundabout after days of heavy fighting, a Syrian official said on condition of anonymity because he was not authorized to speak to the media.

Heavy shelling also was reported in Taibeh, a town near Homs, an early center of the uprising. Opposition activists said at least 10 people were killed and dozens were wounded.

Amateur video from Taibeh, posted Saturday, showed several badly disfigured bodies being pulled from the back of a pickup truck by distraught bystanders. One body was carried away on a red stretcher.

In another video, masked rebel fighters posed with assault rifles in what they said is an air defense base east of Damascus they captured earlier in the week.

The video showed captured weapons, including anti-aircraft missiles, heavy machine guns and large-caliber ammunition. The rebels surrounded a group of captured regime soldiers. The captives, some with bandages on their heads, each stood up and gave their rank and name.

The authenticity of such videos cannot be confirmed independently because Syria imposes tight restrictions on foreign journalists.

In a success for the opposition activists said, rebel fighters took control of the village of Khirbet el-Jouz in Syria's northwestern Idlib province, about 10 miles from the Turkish town of Guvecci.

Turkey's state-run Anadolu Agency said that rebels planted their flag on the roof of a building that had been used as a base by regime troops in the village. The takeover came after intense clashes, with mortar shells exploding at a relentless pace, some near the Turkish border, Anadolu said.

Two of the mortars from that battle landed in Turkey, and a third shell hit later in another village in Turkey's Hatay province. No casualties were reported, but Turkish forces returned fire each time, according to Anadolu and the Hatay governor's office.

Earlier this week, Turkey's parliament approved such retaliation, expanding Turkey's response options. Turkey's leaders have reiterated that they don't want war with Syria, but another dramatic or deadly border incident could force unwanted escalation.

In another international entanglement, Assad ally Iran appealed to rebel backers Turkey and Qatar to help release 48 Iranians purportedly being held by Syrian rebels since August.

In amateur video posted late Thursday, rebels threatened to kill the captives by the end of the weekend unless the regime halts military operations against the opposition.

Iran's Foreign Minister Ali Akbar Salehi spoke by phone Saturday with the Qatari prime minister and the Turkish foreign minister and received assurances they would try to help, Iran's state news agency IRNA reported.

Iran says those abducted were pilgrims visiting a Shiite shrine in Damascus. The Syrian opposition claims they are members of the elite Revolutionary Guard helping the Syrian regime.