ZAMBOANGA CITY: A powerful explosion ripped through a lodging house in the southern Iligan City, but there were no immediate reports of casualties, officials said.

Officials said that the blast on Monday occurred in Room 1 of Negra Lodging House and investigations are still going on.

“We still don’t know the cause of the explosion. No casualty was reported and no explosive fragments were found,” Brig. Gen. Daniel Lucero, commander of the 103rd Infantry Brigade, told the Mindanao Examiner newspaper.

No other details were made available by the military, but Lucero said that the room was empty when the explosion occurred.

Just in May, three people were killed and over two dozens injured in a bomb explosion in Iligan. Authorities did not say who were behind the attack.