Sudan's President Omar al-Bashir has travelled to Indonesia, defying an international warrant for his arrest, to attend an Organisation of Islamic Cooperation summit.

The meeting, which began on Sunday, is dedicated to the Israeli-Palestinian conflict and brings together officials from 57 countries.

Bashir managed to fly under the radar of Indonesian human right activists and NGOs. Last year, he cancelled a trip to attend an Asia-Africa conference in the capital Jakarta after protests by rights groups who wanted the president arrested.

"The same human rights groups now question the morality of this summit - discussing peace and human rights in Palestine - as the topic is being discussed with someone who has been accused of violating the same rights of his own people," Al Jazeera's Step Vaessen reported from the conference venue.

The Hague-based International Criminal Court (ICC) issued arrest warrants for Bashir in 2009 and 2010, accusing him of masterminding genocide and other atrocities in his campaign to crush a revolt in Sudan's western Darfur region.

Members of the ICC are obliged to act on arrest warrants. Indonesia is not a member.

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Bashir, who has ruled Sudan since an army-backed 1989 coup, rejects the ICC's authority.

But he had not travelled outside the Middle East or Africa since 2011, until he visited China in September to attend celebrations commemorating the end of World War II. China is also not a member of the ICC.

In June, Bashir was forced to flee South Africa after a court ruled he should be banned from leaving pending the outcome of a hearing on his possible arrest.

At the OIC summit in Jakarta, Indonesia's President Joko Widodo urged Muslim nations to be part of the solution to the Israeli-Palestinian conflict, rather than part of the problem.

Widodo said on Monday that the entire world is concerned by the deterioration of the situation in Palestine. "If the OIC cannot be part of the solution to Palestine, then the OIC becomes irrelevant," he said.