DUBAI - The Saudi navy has captured three members of Iran’s Revolutionary Guard Corps (IRGC) from a boat seized last week as it approached the kingdom’s offshore Marjan oilfield, the Saudi information ministry said on Monday.

Relations between the two countries are at their worst in years, with each accusing the other of subverting regional security and support opposite sides in conflicts in Syria, Yemen and Iraq.

“This was one of three vessels which were intercepted by Saudi forces. It was captured with the three men on board, the other two escaped,” a statement from the ministry’s centre for international communications said.

“The three captured members of the Iranian Revolutionary Guard are now being questioned by Saudi authorities,” it said, citing a Saudi official.

Revolutionary Guards kill leader of militant group

The leader of a Sunni Muslim militant group was killed by the Revolutionary Guards in southeast Iran during operations in recent days, the Islamic Republic News Agency (IRNA) reported on Monday.

Three members of the Ansar al-Furqan group, which has attacked security forces and civilians, according to Iranian officials, were also killed by Iranian forces in the southeast region of the country last week, state media said.

Jalil Qanbar-Zahi, leader of Ansar al-Furqan, had been pursued by Iranian security forces for 25 years and was killed by the Guards near the city of Qasr Qand, IRNA reported.

Iranian security forces have carried out a string of raids and arrests after a complex terror attack last week targeted the Iranian parliament in Tehran and the shrine of the founder of the Islamic Republic, Ayatollah Ruhollah Khomeini, south of the capital, leaving 18 dead.

Islamic State claimed responsibility for that attack.

On Sunday night, the Guards fired half a dozen missiles from western Iran at Islamic State targets in eastern Syria in what Guards commanders said was a message the perpetrators of the Tehran attack and their supporters, state media said.

Iran’s restive Sistan and Baluchestan province, in the southeast of the country on the borders with Pakistan and Afghanistan, is home to the Baluch minority and is a hotbed of militant activity against the government of the Islamic Republic.

The province, one of Iran’s most impoverished, is also part of a well-known drug trafficking route.

Qanbar-Zahi was wanted for an attack on a Shi’ite religious ceremony in the city of Chabahar, planning suicide attacks and killing police officers among other crimes, according to IRNA.

During the operations which led to Qanbar-Zahi’s death, the Revolutionary Guards found a car bomb containing 600 kilograms of explosives, 15 suicide bombs, 700 kilograms of explosive material and tens of thousands of bullets, IRNA reported.

Ansar al Furqan is a splinter group of Jundallah, a militant group that also carried out several attacks in the province, according to the Mashregh news site.

Abdolmalek Rigi, the head of Jundallah, was captured and executed by Iranian authorities in 2010.