SEOUL » As Francis became the first pope in 25 years to visit South Korea on Thursday, Seoul’s never-timid rival, North Korea, made its presence felt by firing three short-range projectiles less than an hour before he arrived, officials said.

Although North Korea declined an invitation to Seoul for the papal visit, Francis plans to reach out to North Korea during his five-day trip in a Mass for peace and reconciliation on the war-divided Korean Peninsula. But Pyongyang has a long history of making sure it is not forgotten during high-profile events in the South.

The apparent test firing was conducted from Wonsan on the North’s east coast and the projectiles flew about 135 miles, according to a ministry official who spoke on condition of anonymity, citing office rules. It wasn’t immediately clear what the projectiles were.

North Korea this year has conducted an unusually large number of short-range missile and artillery test firings. Pyongyang has expressed anger over annual military drills between the United States and South Korea, which it says are invasion preparations. A new round of the drills, which Seoul and Washington call routine and defensive, are expected to start in coming days.

During his visit, Francis also plans to beatify 124 Korean martyrs and encourage a vibrant and growing local church seen as a model for the future of Catholicism.

At an airport just south of Seoul, the pope shook hands with four relatives of a South Korean ferry sinking that killed more than 300 and two descendants of Korean martyrs who died rather than renounce their faith.

Some elderly Catholics wiped tears from their faces, bowing deeply as they greeted the pope. A boy and girl in traditional Korean dress presented Francis with a bouquet of flowers. The pope then stepped into a small, black, locally made car for the trip into Seoul, where he and President Park Geun-hye were expected to make speeches.

As his plane flew through Chinese airspace on the way to South Korea early Thursday, Pope Francis sent a telegram of greetings and prayers to Chinese President Xi Jinping. It was a rare opportunity for an exchange since the Holy See and Beijing have no diplomatic relations, and furthers a low-key push for better relations with China and efforts to heal a rift between the Chinese authorities and those Catholics who worship outside the state-recognized church.

Vatican protocol calls for Francis to send telegrams to heads of state whenever he flies through their airspace. Usually they pass unnoticed, but Thursday’s telegram was unique because the last time a pope wanted to fly over China, in 1989, Beijing refused.

Vatican officials say there is a dialogue with Chinese authorities. But the core issue dividing them — Rome’s insistence on naming bishops — remains.

Relations between Beijing and Rome have been tense since 1951, when China severed ties with the Holy See after the officially atheistic Communist Party took power and set up its own church outside the pope’s authority. China persecuted the church for years until restoring a degree of religious freedom and freeing imprisoned priests in the late 1970s.

For the Vatican, the main stumbling block remains the insistence of the state-sanctioned Chinese Catholic Patriotic Association to name bishops without papal consent to administer over the country’s estimated 12 million Catholics.

Other highlights of Francis’ visit include his participation in a Catholic festival for young believers from around Asia. A ceremony Saturday to beatify Korean martyrs who perished for their faith from 1791 to 1888 could draw about 1 million people, South Korea’sYonhap news agency reported.

Authorities in North Korea declined an invitation by the Seoul archdiocese to send a delegation to attend a Mass, the Vatican said.

A few women forced into sexual slavery by the Japanese military during World War II will attend a Mass, although no private audience is expected, the Vatican said. The pope is also expected to meet with some families of the South Korean ferry sinking in April. The government’s response to the disaster, which killed mostly high school students, has angered many South Koreans.

"A lot of bad things keep happening in our country right now, and people are going through tough times. So I hope this event can encourage people and bring more positive things to our country," said Ryun Sun-hee, a 19-year-old college student.

It’s the first papal visit since Pope John Paul II traveled to South Korea in 1989. In January, Francis plans to visit Sri Lanka and the Philippines.

South Korea’s church, which has been growing steadily over the last half century, is seen as a model for the future. Local church officials hope for a continuing increase in believers in a country that once welcomed missionaries to help spread the faith but now sends its own priests and nuns abroad to evangelize in other countries.

There was high anticipation in South Korea ahead of the visit. Banners and posters welcoming the pope decorated streets and subway stations. Yonhap reported an increase in sales of rosaries and other Catholic goods, and special displays of books on the pope and Catholicism have sprung up in book stores.

AP writer Christopher Bodeen in Beijing contributed to this story.