Uganda military authorities said two people died before executing a suspected explosive attack near a Catholic shrine in the capital, Kampala.

The military said in a statement Tuesday they “intercepted and neutralized two armed terrorists” in Munyonyo, a Kampala suburb.

The deceased were a man and a woman on a passenger motorcycle. The female passenger appeared to explode as a group of security forces tracking the duo drew near the suspects, police spokesman Kituuma Rusoke said.

Rusoke did not provide more details and said an investigation is underway.

Uganda is marking a holiday Tuesday to remember a group of Christian martyrs who were killed between 1885 and 1887 on the orders of a local king. The event attracts pilgrims to a different site near Kampala where dignitaries, including Ugandan President Yoweri Museveni, have gathered for mass.

Explosive attacks are rare in Uganda, but authorities sometimes warn of plans by extremist militants opposed to Museveni’s government.