THE HAGUE, Netherlands (AP) — An Islamic radical accused of involvement in destroying historic mausoleums in the Malian desert city of Timbuktu goes on trial at the International Criminal Court on Monday and has already told judges he intends to plead guilty.

A swift and relatively straightforward conviction is expected, marking only the fourth conviction since the Hague-based court was established in 2002. If convicted, he faces a maximum sentence of up to 30 years.

But activists say the court is missing an opportunity to file more charges against the al-Qaida-linked radical, Ahmad Al Faqi Al Mahdi, for war crimes including rape and sexual slavery.

Prosecutors allege Al Mahdi was a member of Ansar Dine, an Islamic extremist group with links to al-Qaida that held power in northern Mali in 2012. The militants were driven out after nearly a year by French forces, which arrested Al Mahdi in 2014 in neighboring Niger.

Al Mahdi was a Timbuktu-based expert on Islamic law recruited to enforce Ansar Dine's strict interpretation of Islam on the occupied Timbuktu, prosecutors told judges at a hearing earlier this year. He allegedly led an organization called the "Hisbah" tasked with upholding public morals and preventing vice.

His lawyer, Jean-Louis Gilissen, told a pretrial hearing in March that Al Mahdi was "concerned with doing what is right, seeking the means to allow his conception of good over evil to prevail."

The radicals destroyed 14 of Timbuktu's 16 mausoleums because they considered them totems of idolatry. The one-room structures that house the tombs of the city's great thinkers were on the World Heritage list and most of them have since been restored.

At the pretrial hearing, Al Mahdi told judges he planned to plead guilty, leading the court to schedule only a week for his trial. Other ICC trials have taken years to complete.

Al Mahdi, who is charged in attacks on nine of the mausoleums and a mosque, is the first suspect to face an ICC charge of deliberately attacking religious or historical monuments. The court's chief prosecutor has likened the case to the destruction last year by Islamic State extremists of historic ruins in the Syrian city of Palmyra.

Human rights activists accuse the "Hisbah" of going beyond targeting buildings and allege that its members also tortured and raped civilians.

International rights group FIDH says its member organizations have documented a litany of crimes and filed a criminal complaint on behalf of 33 victims in Malian courts naming Al Mahdi and 14 others as alleged perpetrators of crimes including rape and sexual slavery.

"We ... deeply regret that the charges against Al Mahdi were not widened to include crimes against the civilian population, including sexual and gender-based crimes, whose victims are far too often ignored during accountability processes," FIDH member organizations said in a statement.