Iran announced the discovery of a secret terror tunnel that was to be used to carry out sabotage attacks in the country, the semi-official state news agency Fars reported on Thursday.

According to Iranian Interior Minister Abdolreza Rahmani Fazli, the tunnel was discovered in the eastern region of the country by security forces.

“We discovered a 40-meter tunnel in the 20-meter depth of the earth in the Eastern parts of the country and they [the terrorists] intended to use it secretly in ripe conditions for conducting explosion and other operations,” Fazli told reporters in Tehran.

“40 people were arrested in this regard,” he added, without specifying the suspects’ identities. 

The use of tunnels to carry out terror attacks has become more commonly associated with Gaza-based terrorist groups, such as Hamas and Islamic Jihad.

During Operation Protective Edge in the summer of 2014 — Israel’s war in Gaza against Hamas — the IDF uncovered and dismantled some 36 terror tunnels, used to ambush, attack, kidnap and kill Israelis.

According to Hamas, Israel was unsuccessful in detecting all of the group’s tunnels. Since the end of the war, Hamas leaders have repeatedly threatened to carry on digging tunnels into Israel to attack civilians and soldiers.

In April, the Israeli defense establishment announced plans to build a sophisticated anti-tunnel barrier along the Israel-Gaza border, which is expected to take two years. The project, known as “Hourglass,” follows a multi-tiered defense strategy, both above and below ground. The project will feature a state-of-the-art fence with advanced sensor technology, see-shoot systems, observation balloons, an underground wall and intelligence-gathering measures.

“The government is investing a fortune in thwarting the threat of tunnels. This is an ongoing effort; it does not end overnight; we are investing in it and will continue to invest steadily and firmly,” Israeli Prime Minister Benjamin Netanyahu told reporters in April.

“Israel will respond forcefully to any attempt by Hamas to attack its soldiers and attack its citizens,” Netanyahu stated. “I’m sure that Hamas understands this very well.”