Israel has decided to once again allow construction materials for UN projects to be brought into the Gaza Strip, the United Nations announced Monday.

The import of construction materials was suspended after the IDF discovered a Hamas tunnel leading out of the Gaza Strip in October that used 500 tons of cement.

According to Robert Serry, the UN special coordinator for the Middle East peace process, the UN is building schools, housing, water and sanitation facilities in the Strip, at a cost of $500 million.

“The situation in Gaza remains concerning,” Serry said in a statement, “and the United Nations is engaged with relevant parties in trying to address the most urgent issues such as energy, water and private sector construction.”

In November, the outgoing commissioner general of the UN Relief and Works Agency for Palestine said that 19 out of its 20 projects had “ground to a halt,” and that UNRWA had not been able to import building materials during the preceding month.

Israel banned the entry of building materials intended for the private sector into the Gaza Strip following the violent takeover of Hamas in June 2007, citing concerns that such materials could be diverted for terrorist purposes. The closure on the Strip was eased somewhat in 2010 at the behest of the International Quartet, and in late 2012 Israel began allowing in 20 trucks of gravel a day for private construction projects.

In September, Israel began allowing 70 trucks a day of gravel, metal bars and cement, for use by private builders, to enter the Gaza Strip for the first time in six years, a decision that was reversed when the tunnel was uncovered.