JERUSALEM, Israel – Hamas is considering whether to renew violence against Israel following weeks of relative calm and lashed out on Monday against Egypt for its role as mediator between the two sides.

"We are examining the possibilities for escalation with Israel against the background of the continuation of the blockade and the delay in the reconstruction of the Gaza Strip,” an unnamed senior Hamas official told Al Jazeera on Monday.

The source was referring to Israel and Egypt’s blockade on the Gaza Strip, which Israel says is necessary to prevent the transfer of weapons to Palestinian terror groups inside the coastal enclave. The Hamas official said Egypt has not kept its pledge to help reconstruct Gaza after the 11-day war between Israel and Hamas in May.

The source accused Egypt of not allowing Palestinians to leave Gaza and cross the Egypt-Gaza border.

“The behavior of Egypt violates its promise to compel Israel in exchange for the resistance’s commitment to calm,” the source said. "We express great dissatisfaction with the conduct of the Egyptian mediators and their withdrawal from their promises to the Gaza Strip. We will not allow the current situation to continue, and we will prove the credibility of our words.”

The source also warned against “Israeli attacks” on Al-Aqsa Mosque, which is located on the Temple Mount, and on “Palestinian prisoners,” said Hamas will “again blow up the situation.” This year’s war in Gaza began after Hamas fired rockets at Jerusalem following escalating tensions in the city.

Since that war, Hamas and Israel have held indirect negotiations aimed at stabilizing a fragile ceasefire between the two sides and are relying on Egypt to mediate those talks.

The Lebanese al-Mayadin network quoted sources as saying that Hamas and other terror groups operating in Gaza have issued an ultimatum to meet their demands by the end of 2021.

Palestinian Islamic Jihad (PIJ) also called for Egypt and Israel to ease the blockade.

"The resistance will not allow the blockade on the Palestinians to continue," said Ahmed al-Mudalal, a senior PIJ official in the Gaza Strip.

Israeli sources told CBN News that despite the blockade, the Kerem Shalom commercial crossing is open for business both importing to and exporting from the Gaza Strip. In addition, some 10,000 Palestinians a day cross into Israel for business and work.

The threats come as Israeli Foreign Minister Yair Lapid prepares to visit Egypt this week for talks with senior officials that are expected to focus largely on the Palestinians. They also came amid an increase in lone-wolf Palestinian attacks against Israelis, which Hamas has praised as important to their cause.