Here is the story from globalpost:

The four protesters leapt out of their seats at a debate on blasphemy and freedom of expression held at the Brussels' Free University (ULB) campus Tuesday evening, baring their breasts and squirting water at Archbishop Andre Leonard as they accused him of homophobia.

The story notes:

[T]he archbishop himself remained composed and apparently at prayer throughout.

The women used water bottles made for blessed holy water, shaped like Catholic statues of the Blessed Virgin Mary. The picture to the left shows Archbishop Leonard picking up and kissing one of the bottles following the disruption.