Gaza, Aug 12 (IANS): The UN Relief and Works Agency for Palestine Refugees in the Near East (UNRWA) has called on the Islamic Hamas Movement to retain from the action of violating its facilities in the Gaza Strip.

In a statement, the UNRWA said it has sent letters of protest to Hamas and condemned the existence and potential use of underground structures, including tunnels, reports Xinhua news agency.

"Initial risk assessments have indicated that the existence of underground structures could have led to further damage," it added.

The statement referred to underground tunnels that Hamas used during the last round of tension between Israel and Hamas-led militant groups in the Gaza Strip that lasted for 11 days and ended on May 21.

The agency has also protested the takeover by Hamas of one of the schools it is operating, "which undermines the inviolability and neutrality of UNRWA premises".

"These actions also stand to compromise the safe return of children to their schools and scuttles UNRWA's efforts to open the schools on time," said the statement.

There has been no immediate response from the Hamas movement.

However, Hamas officials said they will study the situation and respond to UNRWA's demand soon.