Pope Leo XIV travelled on Tuesday to the Algerian city of Annaba, the one-time home of Christian theologian Saint Augustine, in the first trip ever by a pontiff to the north African country.

Leo's visit, which marked the start of an African tour, was marred on Monday by two suicide attacks in Blida, some 45 kilometres (28 miles) southwest of the capital Algiers, and by sharp criticism by US President Donald Trump.

Still, the pope said on Tuesday that the trip "is for me a special gift from God's providence", thanking authorities for "ensuring (its) success".

Leo was travelling back to Algiers on Tuesday evening and is set to leave the country for Cameroon on Wednesday.

While the authorities have yet to comment on the suicide attacks, an informed source on Tuesday confirmed the bombings to AFP, and widely circulated videos of the bodies of two suicide bombers were verified by AFP. 

No other deaths were confirmed, and no link has so far been established between the attacks and the pope's visit.

The American pope's trip was already at risk of being overshadowed by a spat with President Trump, who said he was "not a big fan" of Leo after the pontiff called for peace in the Middle East.

Aboard the papal plane en route to Algiers on Monday, Leo told reporters that "the Gospel says... blessed are the peacemakers", and that he had nothing to fear from Trump.

The US president later doubled down on his criticism, refusing to apologise and calling Leo "wrong" and "weak".

Italian and American bishops expressed their support for the pope, as did Trump's ally Italian Prime Minister Giorgia Meloni, who called the US leader's remarks "unacceptable".

Overnight, US Vice President JD Vance urged the Vatican to "stick to matters of morality", and let Trump "stick to dictating American public policy".

- 'Son' of Augustine -

The controversy aside, in northeast Algeria in Annaba -- formerly the ancient Roman city of Hippo -- Leo visited vestiges of the city's past, and a reception centre run by Catholic nuns for impoverished elderly people, mostly Muslims.

The city was once the home of Augustine, whose autobiographical "Confessions" is a seminal work within the Christian tradition.

The pontiff has previously referred to himself as a "son" of the saint, and belongs to the Augustinian order.

Leo also celebrated Mass at the hilltop Basilica of Saint Augustine in the presence of clergy from across Africa. The Arab-Byzantine-style church draws some 18,000 pilgrims each year, including Muslims and Jews.

Among those in attendance was Sister Rose-Marie de Tauzia, who has lived in Algiers for two decades. She said she was happy with the pope's visit, adding he had come to "proclaim peace" at a time "when everything is difficult" and "the world is in tension".

Delivering his homily in French, the pontiff told Algeria's Christians they were "a humble and faithful sign of Christ's love in this land".

"Bear witness to the Gospel through simple gestures, genuine relationships and a dialogue lived out day by day," he said.

Algerian media outlets praised the pontiff's visit, with Le Quotidien d'Oran saying it showed that "Algeria is a land committed to peace".

Sunni Islam is the state religion in Algeria, and Catholics represent less than 0.01 percent of the 47 million inhabitants.

In his first speech in Algiers on Monday, Leo paid tribute to victims of the country's 1954-1962 war of independence from France and called for "forgiveness" at a time of heightened tensions between Algeria and its former colonial ruler.

The pope also urged Algeria's leaders "not to fear" greater public participation in political life, calling for a "vibrant, dynamic and free civil society".

Since the pro-democracy Hirak protests in 2019, which called for sweeping reforms and greater transparency, human rights groups have reported shrinking freedoms and greater controls over public space.

After Cameroon, the pope will be travelling on to Angola and Equatorial Guinea.