The UK government has said it is “appalled” by reports that Israel deliberately fired on United Nations bases in southern Lebanon.
On Thursday, two UN peacekeepers from Indonesia were wounded falling from an observation tower in Naqoura after an Israeli tank fired towards it.
Two other peacekeepers were injured in a separate explosion which the Israeli military (IDF) has said it is investigating.
Last week, the Israeli military asked the UN to prepare to pull back from the border - something Unifil (the United Nations Interim Force) has refused to do.
IDF Spokesman Lt Col Nadav Shoshani said the military was in an "ongoing conflict with Hezbollah whose terrorists and infrastructure are in close proximity to Unifil positions posing a significant risk to the safety of peacekeepers".
"The IDF takes every precaution to minimize harm to civilians and peacekeepers alike," he added.
UN General Secretary Antonio Guterres said firing on peacekeepers was a “violation of international humanitarian law”.
"These peacekeepers must be protected," he said.
Andrea Tenenti, a spokesman for Unifil, said recent attacks on UN bases look like "more of a deliberate attack against our troops, who have been in the south to try to bring back stability".
Asked about the attacks, a Downing Street spokesperson said it was "vital that peacekeepers and civilians are protected” and reiterated calls for an immediate ceasefire.
"As you know we continue to call for an immediate ceasefire and an end to suffering and bloodshed. It is a reminder of the importance of us all renewing our diplomatic efforts to resolve this."
Asked if the prime minister would agree with Ireland's Taoiseach (Irish PM) that Israel had broken international law, the spokesperson says: "All parties must always do everything possible to protect civilians and comply with international law."
Unifil was set up in March 1978 to monitor the area after Israel's invasion of southern Lebanon - a response to cross-border attacks by the Palestine Liberation Organisation.
Indonesia currently contributes the largest number of personnel to the force, followed by India, Ghana, Nepal and Italy. Since its creation, more than 300 Unifil peacekeepers have been killed.