Turkish armed forces have launched artillery attacks against Syria in response to a Syrian mortar strike which killed five members of the same family in southeastern Turkey.

In a statement issued on Wednesday, Recep Tayyip Erdogan, the prime minister, said the attacks, carried out following radar tracking, were within the rules of engagement.

"There has been an attack on Turkey's mainland and its citizens lost their lives. There is definitely a response to it in international law ... We are not blinded by rage but we will protect our rights to the end in the face of such an attack on our soil that killed our people", said Bulent Arinc, Turkish deputy prime minister.

Al Jazeera's Andrew Simmons, reporting from Antakya, on the Turkish-Syrian border, said the deputy prime minister's mention of "certain responsibilities" contained within NATO treaty articles, could mean Ankara responsed without consulting international bodies first.

Western officials, from Anders Fogh Rasmussen, NATO secretary-general, to Hillary Clinton, US secretary of state, quickly condemned the attack that struck a house in the border town of Akcakale.

Clinton said the White House was "outraged" by the "very dangerous situation" created by the attack.

Ankara has agreed to convene an urgent meeting of NATO members in Brussels to discuss the shelling. The meeting of NATO ambassadors falls under Article 4 of the NATO charter which provides for consultations when a member state feels its territorial integrity, political independence or security is under threat.

At the meeting, currently under way, our correspondent said Turkey may argue it was "fully entitled to respond" in the manner in which it did.

Witnesses said policemen have also been injured in the shelling, which originated only kilometres away from the Syrian border.

Ahmet Davutoglu, Turkey's foreign minister, briefed Ban Ki-Moon, UN chief, on the situation shortly word of the attack reached Ankara.

Though this the mortar attack marks the third instance of Syrian gunfire or artillery reaching Turkish territory, it is the "first time Turkey has actively become involved" in the situation, said our correspondent.

Calling it a "very serious escalation", Simmons said the last time there was such tension between the neighbouring countries was when a Turkish war plane was downed in June. However, Turkey did not retaliate in that instance.