Three Palestinian gunmen and an Israeli civilian were killed after the Hamas militant group, which controls the Gaza Strip, carried out its most intensive shelling of Israel since the 2014 Gaza war in retaliation against a botched cross-border commando raid, Reuters reported. One Israeli woman is in a critical condition, reported AFP.

Israel responded with air strikes that targeted a Hamas intelligence compound, a radio building and the studios of Al-Aqsa television, whose employees had received advance warnings from the military to evacuate.

On Sunday, a covert Israeli operation in Gaza, the reason for which is not known, had left at least seven Palestinians dead, including one senior Hamas military commander, The New York Times reported. In television interviews, Tal Russo, a former Israeli military commander in charge of long-range missions, said it had been an intelligence operation, and not an assassination or abduction mission.

The fighting has put at risk months of multilateral talks aimed at bringing down tensions on the Gaza border. In October, Israel ordered the reopening of the Kerem Shalom and the Erez crossings following a reduction in violence. The Kerem Shalom crossing at the junction of the Gaza Strip and Israel border is used by trucks to transport goods from Israel or Egypt to the Palestinian territory while people use the Erez crossing.

Some 170 Palestinians were killed and thousands more were wounded earlier this year after Israel used lethal force against thousands of Palestinians in Gaza who, in March, started the “March of Return” protest demanding that refugees be allowed to return to their homes that are now in Israeli territory.