The Ministry of Foreign Affairs and Trade has beefed up its travel advisories for Israel, the occupied Palestinian Territories, and Papua New Guinea.
It has warned of "extreme risk" to security for travellers entering the West Bank and Gaza, as they may get caught up in acts of terrorism and retaliatory military violence. It advises against all travel.
"Clashes between armed Palestinian groups and attacks on individuals in Gaza intensified in May resulting in deaths and injuries," MFAT said. "The security situation remains volatile as it also does in the West Bank."
Travellers are also advised to avoid areas bordering Lebanon, and along the Israeli side of the border with Gaza Strip. Care should also be taken at the crossing points between Israel and Jordan, the ministry says.
It warns there is "some" risk to security for visitors to Israel and advises caution.