RIYADH, July 16: A car exploded at a checkpoint near Saudi Arabia's highest security prison at sunset on Thursday, killing the driver and wounding two security officials, the interior ministry said.

State television said the driver was a teenager on the run after killing his uncle, who triggered the blast after officers surrounded his vehicle south of the capital Riyadh.

But the use of an explosive so close to a prison holding hundreds of Islamist detainees will stoke fears of a growing threat of militancy in the world's top oil exporter.

The Islamic State group has called on supporters to carry out attacks in the kingdom and killed 25 people in two suicide bombings at Shi'ite Muslim mosques in the country's east in May.

"While security officers were manning one of the security checkpoints on Ha'er Road in Riyadh, they directed the driver of a suspected car to stop. The driver initiated an explosion which led to his death," the ministry said in a statement.

The road runs south from Riyadh to Ha'er prison, home to 1,375 detainees who were mainly convicted of militant crimes, its director told Reuters during a visit there this month.

The Ekhbariya state TV station, citing unamed sources, said the teenage driver had killed his uncle that afternoon, then ran off with his car.

The driver had tried to drive past bypass the checkpoint, then set off an explosive as security forces tried to surround him, it added.

The detention of thousands of Saudi Islamists accused or convicted of militancy over the past decade has angered many conservative Sunni Muslims in the kingdom, prompting some rare protests from 2011-13.

Two Saudis linked to a suicide bombing in Kuwait last month took part in those protests, local media reported at the time.