Pope Francis's weekly general audience at the Vatican on Wednesday was briefly interrupted by two women from an animal rights group, who shouted and held up signs against bullfighting.

The women walked down an aisle in the Vatican's Paul VI hall holding signs and wearing white t-shirts with slogans such as "Bullfighting is a sin" and "Stop blessing corridas," the Spanish term for the controversial spectacle.

They were quickly escorted out of the venue by security officials.

Francis was holding his first general audience on Wednesday after a month-long summer break during July, as he prepares for a hectic period of travel and major debates over the Catholic Church's future.

Wednesday's audience was taking place in the Vatican's audience hall, instead of St. Peter's Square, because of the high heat in Rome.

The two women wore shirts identifying them as part of the People for the Ethical Treatment of Animals (PETA) organisation. It was at least the second protest by persons affiliated with the group at a papal event this year.

In January, two women held a similar protest about bullfighting during a prayer service featuring the pope at Rome's Basilica of St. Paul Outside the Walls.

The activists contend that some Catholic priests offer blessings to local bullfighters.

Francis, who has made protection of the environment a signature part of his 11-year papacy, is not known to have commented on the issue. But one of his predecessors, the 16th-century Pope Pius V, did outlaw bullfighting, calling the practice "better suited to demons rather than men."

Traditional bullfights take place in Spain, France and several Latin American countries, and in Portugal where the bull is not killed in the ring.