Turkey’s armed forces have continued attacking targets inside Syria after parliament authorised foreign military operations – but the government says it is about deterrence, not war.

Syria has apologised for the mortar strike which killed five civilians in Turkey on Wednesday – and despite Ankara’s show of strength along the border, it seems neither neighbour wants open conflict.

Turkey says it is only seeking to protect its rights.

“The Syrians accept that they carried out the attack and they apologise. They say nothing like this will happen again. The United Nations mediated and spoke to Syria in the evening and Syria made these statements through the United Nations,” said Turkish Deputy Prime Minister Beşir Atalay.

This is the most serious cross-border escalation of the 18-month-old Syrian uprising. Turkey had already increased its military presence along the border and the prime minister has previously threatened retaliatiation.

World leaders have condemned the Syrian mortar strike on Akcakale but have urged restraint.

Unconfirmed reports say Syrian troops have died in the Turkish reprisals.