BUDAPEST: British Foreign Secretary Wiliam Hague expressed "strong solidarity with our NATO ally Turkey" on Thursday, after Syrian shelling killed five Turkish citizens inside Turkey.

Speaking at a press conference in Budapest after meetings with Hungary's Prime Minister Viktor Orban and Foreign Minister Janos Martonyi, Hague said the Syrian regime must "make sure that there will be no repeat whatsoever of such incidents".

Hague said the shelling, which Syria has said was accidental, was "completely unacceptable not only for Turkey but for the international community as a whole".

"The longer the crisis in Syria goes on the greater will be the danger to peace and the threat to the neighbouring countries," he added.

"That is why it is so important for the UNSC to pass a more decisive resolution," he said.

Referring to Turkey's shelling of Syrian positions in retaliation, Hague said the military reaction was "understandable", but added that it was important for Ankara to see that the whole world is making clear to Syria that there must be no repeat of this incident.

"That message should come not only from western countries but from the Arab world, from Russia, from China, and the whole of the United Nations Security Council, that will help Turkey to respond in an appropriate way," he said.

The British foreign minister was visiting Budapest to attend a conference on cybersecurity.