As contingency plans are rolled out to support British nationals in Lebanon and the region, the UK foreign ministry said in a statement around 700 troops, backed by the border force, would move to Cyprus in the coming hours.

The air force also have aircraft and transport helicopters on standby to provide support if necessary, the ministry added.

“Events in the past hours and days have demonstrated how volatile this situation is, which is why our message is clear, British nationals should leave now,” defence secretary John Healey said.

Fierce fighting this week between Israel and Iran-backed Hezbollah has increased fears that nearly a year of conflict will explode and destabilise the Middle East, where a war between Hamas and Israel is already raging in Gaza.

Israel has said it is shifting its focus from Gaza to the northern frontier, where Hezbollah has been firing rockets into Israel in support of Hamas.

Israel’s offensive since Monday morning has killed 569 people, including 50 children, and wounded 1,835 in Lebanon, health minister Firass Abiad told Al Jazeera Mubasher TV.

Thousands of displaced people who fled from southern Lebanon were sheltering in schools and other buildings.