Seven people have been arrested in occupied East Jerusalem on suspicion of planning attacks for Iran, the Israeli security services say, the second such case in as many days.

The Shin Bet domestic security agency and police said in a joint statement that the suspects had planned, “under Iranian direction,” to assassinate a senior Israeli scientist and a city mayor.

They were also tasked with bombing a police car and throwing a grenade at a house, for a payment of some 200,000 shekels (£40,700; $53,000), authorities said.

News of the detentions comes a day after Israeli security services announced that seven Israelis had been arrested on suspicion of spying for Iran.

Iran is Israel’s arch-foe and tensions between the two countries are at their highest for years. Israel has pledged to retaliate against an Iranian missile attack on Israel on 1 October.

The statement said the group was led by a 23-year-old man, who had allegedly been recruited as an Iranian operative. The leader is said to have recruited the six other suspects.

Local media said the man had confessed to carrying out “terrorist activity” for nationalistic reasons.

The Shin Bet and police statement said: “Scientists, mayors, security officials, and other prominent Israelis are targets for Iranian agents.

“This investigation underscores Iran’s efforts to recruit Israeli citizens for terrorism.

“Israeli security agencies will continue collaborating to detect Iranian activities and prosecute those involved.”

News of the arrests came hours after authorities said seven Israeli Jewish citizens had been arrested on suspicion of spying for Iran.

The seven – who had immigrated from Azerbaijan – were detained in the Haifa area.

They are suspected of carrying out about 600 espionage missions, including passing on intelligence about military sites and energy infrastructure. Last week, four Israeli soldiers were killed in a drone attack by Iran’s ally Hezbollah on an army base near Binyamina in northern Israel. The base was among the sites which the group had spied on, security services say.

While Iranian attempts to recruit local operatives is not unusual, the alleged recruitment of Israeli Jews is very rare.

A statement from the Shin Bet and police said those arrested were “well aware” that the intelligence they provided compromised national security and could potentially aid enemy missile attacks.

They were paid hundreds of thousands of dollars for the information said police, who also described it as one of the most serious cases yet uncovered.

The latest arrests come amid stepped up overt and covert activity between Israel and Iran, including intelligence and sabotage operations in each other’s countries.

Israel is believed to have penetrated Iranian security services, resulting in attacks and assassinations. Iran occasionally announces arrests of alleged Israeli intelligence agents and the breaking up of alleged Israeli spy cells, though without providing substantial evidence.