Iran executed an individual on Saturday accused of spying for Israel, the judiciary’s Mizan news agency reported on Sunday, citing an Iranian prosecutor, Reuters has reported.

The individual was alleged to have links to the Israeli intelligence agency Mossad and to have leaked classified information, according to the judiciary official cited by Mizan.

Entangled in a decades-long shadow war with Israel, Iran has executed many people it has accused of maintaining links with Israeli intelligence and facilitating its operations within the country.

READ: Tehran executes ‘top Mossad agent’ amid rising fears of internal subversion

Amid rising tensions following a series of deadly attacks in Iran’s southeast, the government has introduced a new law imposing harsher penalties on those accused of spying for Israel or the United States.

On Wednesday, legislation came into effect increasing prison terms and possible sentences for espionage-related offences involving “hostile governments”, particularly Israel and the US, according to reports in Iranian media.

Separately, Iran’s Islamic Revolutionary Guard Corps (IRGC) announced on Sunday that at least four people were killed in attacks in Sistan-Baluchestan Province, which the Guard attributed to “groups affiliated with Israel”.

The incidents occurred on unspecified dates in the restive southeastern province, one of Iran’s least developed regions and home to a large Sunni Baluch population, in contrast to the country’s Shia Muslim majority.

In a statement published by the Guard’s official outlet, Siba News, the IRGC accused “mercenary groups linked to the Israeli regime” of killing “several Sunni tribal leaders”.

Sistan-Baluchestan, which borders Pakistan and Afghanistan, has long been a flashpoint for violence involving Baluchi separatists, Sunni militant groups and drug traffickers. Iranian authorities frequently accuse jihadist organisations active in the area of maintaining ties with Israel.

READ: Iranian court gives lengthy jail sentences to two French citizens for spying