The Islamist Hamas rulers of the Gaza Strip confirmed Wednesday that two of the group’s members died when a tunnel collapsed as they were working on it in the south of the coastal enclave.

Hamas said that field commander Fuad Abu Atewi and fighter Ahmad Haider al-Zahar were killed Tuesday outside Khan Younis, which is near the Strip’s border with Egypt.

Last week, the group confirmed that seven of its members were killed in a tunnel collapse in northern Gaza.

The collapse on January 26 occurred amid heavy winter rain. Hamas accused Israel of causing the collapse by opening dams to flood Gaza with water — an annual claim made by Palestinians and flatly rejected by Israel. There are no dams in southern Israel.

Relatives mourn during the funeral of Hamas militant Ahmed al-Zahar, killed during a tunnel collapse, during his funeral in the village of Al-Moghraga near the Nuseirat refugee camp in the central Gaza Strip on February 3, 2016. (AFP / MAHMUD HAMS)

Relatives mourn during the funeral of Hamas militant Ahmed al-Zahar, killed during a tunnel collapse, during his funeral in the village of Al-Moghraga near the Nuseirat refugee camp in the central Gaza Strip on February 3, 2016. (AFP / MAHMUD HAMS)

In a bid to keep a lid on last week’s disaster, Hamas forbade local media from reporting the incident.

Recent reports said Hamas has been accelerating its tunnel-digging program.

Several days ago, the head of the Eshkol Regional Council, Gadi Yarkoni, told Israel Radio that many residents have been complaining of hearing — and feeling — increased underground digging activity in recent weeks.

Prime Minister Benjamin Netanyahu and other Israeli leaders have warned Hamas, which Israel and many Western countries consider a terror group, not to prepare new tunnel attacks. Hamas’s former prime minister, Ismail Haniyeh, bragged on Friday that his group has been advancing its tunnel construction and rocket production ahead of a future conflict with Israel.

In the lead-up to the war in Gaza in 2014, Hamas built a sophisticated network of tunnels that it used to penetrate Israel and attack soldiers near the border. During the conflict, the IDF destroyed dozens of those tunnels. Other tunnels are used by the group as part of its defensive infrastructure as well as to smuggle people and goods in and out of Egypt’s Sinai peninsula.

The Strip has been subject to a blockade by Israel and Egypt, designed in part to prevent Hamas from importing arms and building new tunnels with imported concrete.

Egypt has embarked on a massive campaign aimed at stemming cross-border smuggling between Gaza and Sinai, where it is fighting an insurgency by Islamist militants. The operation has included flooding hundreds of tunnels that once dotted the border region and building a 500-meter-wide buffer zone filled with seawater.