ISTANBUL -- Stepping up its response to a deadly mortar attack launched from Syria, the Turkish government on Thursday easily won blanket approval from Parliament for military operations outside its territory as its military shelled targets across the border for a second day.

The two moves suggested that Turkey is preparing to take a more aggressive stance against Syria in the wake of an incident Wednesday in which mortar shells killed a woman, three of her children and a neighbor in the Turkish border town of Akcakale, where rebels seeking to topple the government of President Bashar Assad recently had seized the Syrian side of the crossing point.

“This was not the first attack of Syria against Turkey,” Turkish Prime Minister Recep Tayyip Erdogan later told a news conference. “There were seven other attacks made by Syria on Turkey in recent times.”

Syria apologized for the incident and promised that it would not be repeated, according to Turkey’s deputy prime minister, Besir Atalay. But Erdogan said another mortar round fired from Syria fell Thursday on the town of Altinozou in Hatay province, where the city of Antakya has become a center for the Syrian rebel movement. It was unclear whether rebel and Syrian forces were clashing nearby. Altinozou is 250 miles west of Akcakale.

“They say it is an accident, a mistake,” Erdogan said. “What kind of accident is this that happens eight times?”

The Obama administration endorsed the Turkish moves as proportional, appropriate and intended to deter, State Department spokeswoman Victoria Nuland said. But the international community remained deadlocked after Syria’s closest ally, Russia, blocked efforts at the United Nations to issue a statement condemning the Syrian shelling.

Syria’s U.N. representative, Bashir Ja’afri, said his government sympathized with those killed in Wednesday’s incident. But he said Turkey, which has long provided support and refuge for anti-Assad rebels, bore part of the blame for failing to heed repeated calls to close the border to infiltration by rebel groups and arms shipments.

"The Turkish government policies toward Syria are wrong and have been wrong since the beginning of the crisis," said Ja’afri.

The Turkish Parliament’s support for future military operations outside the border raised the prospect of a war between the Turkish and Syrian governments, which were once friendly but have been openly hostile toward one another over the past year as Assad violently suppressed what had started as a peaceful opposition movement and has now become a full uprising against him. The Parliament’s action also would allow Turkey to move against Kurdish separatist forces that have taken shelter inside Syria’s Kurdish region.

Erdogan denied that Turkey was seeking a wider conflict with its neighbor. “We could never be interested in something like starting a war,” he said. But he added that Turkey would protect its citizens and its borders, and “no one should try and test our determination in that regard.”

How far Turkey will press the matter remains to be seen, however. With U.S. backing and support from NATO, Turkey could use the confrontation to use its ground, artillery and air forces to carve out a buffer zone inside Syria that it has long sought to cope with the 90,000 Syrian refugees who’ve flooded into Turkey in recent months.