Three people killed in an explosion during a Catholic mass in Mindanao, Philippines

Authorities in the Philippines report that an explosion during a Catholic Mass has left three persons dead and nine injured.

The event happened on Sunday morning in the gymnasium of Mindanao State University (MSU) in the city of Marawi.

A five-month conflict between government forces and terrorists affiliated with the Islamic State took place in the city in 2017.

The "senseless and horrible" violence "very saddened and shocked" the university.

"A civilized society cannot tolerate violence, and it is especially repugnant in an academic institution such as MSU," the statement read.

"We are united with our Christian community and everyone impacted by this unfortunate event."

The university also announced that more security personnel had been brought onto the campus and that all classes would be postponed indefinitely.