Israel tightened its blockade of the Gaza Strip on Tuesday, partly over kites carrying firebombs to set alight Israeli farmland, as concerns mounted over whether the rudimentary devices could spark another war.

Days after the heaviest exchange of fire between Israel and Palestinian militants in Gaza since a 2014 conflict, Israel said it was blocking until Sunday fuel deliveries to Gaza through its only goods crossing with the enclave.

The fishing zone enforced by Israel off the Gaza Strip was also reduced from six nautical miles to three.

The goods crossing, known as Kerem Shalom, will remain open for food and medicine on a case-by-case basis.

It had already been closed to most deliveries since July 9, partly in response to the firebombs.

The move followed months of tension that has raised the possibility of a fourth war between Israel and Gaza militants since 2008.