Updated 6:38 PM ET
ISTANBUL Turkish artillery fired on Syrian targets after deadly shelling from Syria hit a Turkish border town on Wednesday, sharply raising tensions on a volatile border that has been crossed by tens of thousands of Syrian refugees fleeing violence in their country.
In a terse statement, the office of Turkey's prime minister, Recep Tayyip Erdogan, condemned shelling that hit the Turkish town of Akcakale, killing five local residents and wounding a dozen others. The shelling appeared to come from Syrian government forces who were fighting Syrian rebels backed by Turkey, which has called for the ouster of Syrian President Bashar Assad.
"Our armed forces at the border region responded to this atrocious attack with artillery fire on points in Syria that were detected with radar, in line with the rules of engagement," the Turkish statement said.
"Turkey, acting within the rules of engagement and international laws, will never leave unreciprocated such provocations by the Syrian regime against our national security," it said.
Along the volatile border, a shell fired from inside Syria landed on a home in the Turkish village of Akcakale, killing a woman, her three daughters and another woman, and wounding at least 10 others, according to Turkish media.
Turkey's NTV television said Turkish radar pinpointed the positions from where the shells were fired on Akcakale, and that those positions were hit.
"Turkey is a sovereign country. There was an attack on its territory. There must certainly be a response in international law. ... I hope this is Syria's last craziness. Syria will be called into account," said Turkish Deputy Prime Minister Bulent Arinc.
Turkish media said Turkey has prepared a parliamentary bill for Syria that is similar to one that authorizes the Turkish military to intervene in northern Iraq in pursuit of Kurdish militants who have bases there. The bill is expected to be discussed in parliament on Thursday, Anadolu agency reported.
If approved, the bill could more easily open the way to unilateral action by Turkey's armed forces inside Syria, without the involvement of its Western and Arab allies.
Secretary of State Hillary Rodham Clinton said the U.S. was "outraged that the Syrians have been shooting across the border," adding that she would speak with Turkish Foreign Minister Ahmet Davutoglu on the matter.
"It's a very, very dangerous situation," Clinton said. "And all responsible nations need to band together to persuade the Assad regime to have a cease-fire, quit assaulting their own people and begin the process of a political transition."
"This is yet another example of the depraved behavior of the Syrian regime, and why it must go," said Pentagon press secretary George Little. "We regret the loss of life in Turkey, a strong ally, and continue to monitor the situation closely."
A statement issued by a U.N. spokesperson on behalf of Secretary General Ban Ki-moon said the secretary general "expresses his deepest concern at the incident" and "extends his sincere condolences to the Government and people of Turkey over this tragic loss of life." The statement added that Ban "has repeatedly warned that the ongoing militarization of the conflict in Syria is leading to tragic results for the Syrian people."
NATO's National Atlantic Council, which is composed of the national ambassadors, held an emergency meeting in Brussels on Wednesday night at Turkey's request to discuss the cross-border incident. A statement on NATO's Web site Wednesday said: "The most recent shelling on 3 October 20l2, which caused the death of five Turkish citizens and injured many, constitutes a cause of greatest concern for, and is strongly condemned by, all Allies.
"In the spirit of indivisibility of security and solidarity deriving from the Washington Treaty, the Alliance continues to stand by Turkey and demands the immediate cessation of such aggressive acts against an Ally, and urges the Syrian regime to put an end to flagrant violations of international law."
Turkey, a NATO ally, is anxious to avoid going into Syria on its own. It has been pushing for international intervention in the form of a safe zone, which would likely entail foreign security forces on the ground and a partial no-fly zone. However, the allies fear military intervention in Syria could ignite a wider conflict, and few observers expect robust action from the United States, which Turkey views as vital to any operation in Syria, ahead of the presidential election in November.
According to Turkey's NTV station, the Syrian information ministry said it had launched an investigation into Wednesday's shelling and expressed sorrow for the deaths of Turkish civilians. But it urged Turkey to prevent the cross-border infiltration of what it called terrorists.
Turkey hosts more than 90,000 Syrian refugees in camps along its border, and also hosts Syrian opposition groups. There is concern in Turkey that the Syrian chaos could have a destabilizing effect on Turkey's own communities; some observers have attributed a sharp rise in violence by Kurdish rebels in Turkey to militant efforts to take advantage of the regional uncertainty.