RIYADH: Four Iranians including an alleged spy will stand trial in Saudi Arabia, local media reported Friday, as a diplomatic crisis festers between the regional rivals.

The Arab News daily reported that three of the suspects are alleged “terrorists” while another is accused of espionage. It gave no details of the accusations.

The Saudi Gazette said they were arrested in 2013 and 2014, but did not identify them.

A fifth Iranian is already serving a 13-year jail term following his conviction for recruiting young Saudis to fight in neighbouring countries, the newspapers said.

Related: Iran reacts with fury after Saudis execute Shia cleric

The reports come after tensions escalated between Saudi Arabia and rival Iran.

Riyadh severed diplomatic ties and air links with Tehran after crowds set fire to its embassy in the Iranian capital and its consulate in second city Mashhad last weekend.

The protests were in response to Riyadh's execution of Shia cleric Nimr al-Nimr, a driving force behind demonstrations in 2011 by the kingdom's Shiite minority, which has complained of marginalisation.