RIYADH, Saudi Arabia - A Yemeni man stabbed three performers during a play in the Saudi capital on Monday, police said, in the first such attack since the kingdom began easing decades-old restrictions on entertainment.

The assailant was arrested after state television footage showed him stomping on to the stage in Riyadh's King Abdullah Park during a musical performance by what appeared to be a foreign theater troupe.

Police said the man arrested was a 33-year-old Yemeni expatriate and that a knife was seized.

But police offered no information about the nationality of the victims or the motivation of the assailant.

The King Abdullah Park is one of the venues hosting the two-month "Riyadh Season" entertainment festival, part of a government push to open up the kingdom to tourists and diversify its economy away from oil.

The country's Crown Prince Mohammed bin Salman has introduced reforms including allowing concerts, reopening cinemas and lifting a ban on women driving as part of a contentious liberalization drive.

In scenes that were unimaginable just two years ago, Saudi Arabia has staged glitzy performances by a host of international artists, from South Korean boy band BTS to pop icon Janet Jackson and rapper 50 Cent.

But some Saudi officials warn that introducing such reforms is fraught with peril.

While they are wildly popular among the young population, the reforms risk angering archconservatives, including hardline clerics and the religious police whose powers have been clipped in recent years.

Agencies