At least 10 were killed, including a suicide bomber, and 40 others injured in twin blasts in the Philippines' Sulu province today, the army said.

Western Mindanao Command chief Lieutenant General Corleto Vinluan said the victims also comprised five soldiers and four civilians, while 18 soldiers and 22 civilians were among the injured in the back-to-back blasts, reports Xinhua news agency.

Lieutenant Colonel Ronaldo Mateo, the spokesman for the army's 11th infantry division based in Sulu, said a bomb attached to a parked motorcycle exploded at 11.53 a.m. in front of a grocery store, while the second occurred at 1 p.m. near the cathedral in Jolo, the provincial capital.

He said troops were deployed in the area to secure the busy street, adding that soldiers and policemen were posted in the area daily to maintain peace and order.

He said the motorcycle was parked beside a military truck just outside the store before the bomb detonated.

"Two to three minutes after the motorcycle was parked, the improvised explosive device went off," he said.

"The second bomb is believed to have been carried out by a suicide bomber," Mateo added.

The military is verifying reports that the second explosion was carried out by a female bomber.

"Most probably these terrorist acts may have been perpetrated by the Abu Sayyaf group," Mateo said.

Jolo has long been a stronghold for the Abu Sayyaf terrorist group.

Twin blasts hit the Jolo cathedral on January 27, 2019, that killed 23 and injured 95..