Foreign Secretary David Lammy has said the UK will be suspending 30 out of 350 arms export licences to Israel.
He said there was a “clear risk that they might be used to commit or facilitate a serious violation of international humanitarian law”.
The items involved in the suspension of arms licences include parts for fighter jets, helicopters and drones.
Mr Lammy said this did not amount to an arms embargo, and the UK continued to support Israel’s right to defend itself.
He said many had raised concerns about British arms export licensing to Israel over its military activity during the war in Gaza.
The foreign secretary said he immediately sought a review of British arms exports to Israel after the Labour government took office in July.
He said the review did not and “could not arbitrate on whether or not Israel has breached international humanitarian law”.
“This is a forward-looking evaluation, not a determination of innocence or guilt,” Mr Lammy said.
But he said the Strategic Export Licencing Criteria state “the government will not issue export licences if there is a clear risk that the items might be used to commit or facilities serious violations of international humanitarian law”.
Mr Lammy said: “It is with regret…the assessment I have received leaves me unable to conclude anything other that for certain UK arms exports to Israel, there does exist a clear risk they might be used to commit or facilitate a serious violation on international humanitarian law.”
He said the partial ban covered items “which could be used in the current conflict in Gaza”.
In a statement, Business Secretary Jonathan Reynolds saod he had “instructed officials to suspend licences for exports to Israel, where we have assessed those items are for use in military operations in Gaza”.
“This is not a blanket ban but targets relevant licences that could be used in military operations in Gaza,” Mr Reynolds said.
The Labour government has called for an immediate ceasefire in the war between Israel and Hamas, the release of all hostages and an increase in the amount of aid to civilians in Gaza.
Some backbench Labour MPs have been urging Prime Minister Keir Starmer to go further and ban British arms sales to Israel.
The US is by far the biggest supplier of arms to Israel, accounting for 69% of its imports of major conventional arms between 2019 and 2023, according to the Stockholm International Peace Research Institute.
The Campaign Against Arms Trade says that since 2008, the UK has granted arms export licences to Israel worth £574m ($727m) in total.
Research by Parliament shows the value of licences granted has declined from £42m in 2022 to £18.2m in 2023.