A militant belonging to the Palestinian terrorist group Hamas was killed Sunday night in a tunnel collapse underneath Gaza City, Israeli media reported. Three other militants were also injured in the cave-in.

Another member of Hamas died in a tunnel collapse this past February. Hamas, an Islamist terror group openly dedicated to Israel’s destruction, said in January that it lost 22 of its members in tunnel collapses in 2016. Also in February, a Hamas engineer was killed when a rocket he was testing exploded.

A senior IDF official told Israel’s Channel 2 in February that Hamas had rebuilt its tunnel infrastructure and rocket arsenal to the levels it maintained before its 2014 war against Israel. Palestinian affairs correspondent Khaled Abu Toameh pointed out last year that Hamas has prioritized building up its terror infrastructure over rebuilding Gazan homes, writing that “the last thing Hamas cares about is the welfare of the Palestinians in the Gaza Strip.”

Hamas spends some $40 million of its $100 million military budget on tunnel construction, according to Israeli and Palestinian sources. An Israeli official estimated last July that Hamas digs some six miles of tunnels every month.

Hamas elected Yahya Sinwar—an influential hardliner convicted by Israel of multiple murders—to be its new Gaza-based chief in February.