Saudi Arabia has intensified a crackdown on dissidents and rights activists after a respite that coincided with the country's G20 presidency last year, Amnesty International said Tuesday.

Saudi authorities "have brazenly intensified the persecution of human rights defenders and dissidents and stepped up executions over the past six months, following a lull... during Saudi Arabia's G20 presidency," the rights group said in a statement.

Since February this year, Iran and its arch-enemy Israel have been engaged in a "shadow war" in which vessels linked to each nation have come under attack in waters around the Gulf in tit-for-tat exchanges.

A recap:

Tunisian security forces have arrested two MPs from an Islamist party opposed to a power grab by President Kais Saied, their party said.

Maher Zid and Mohamed Affes of Al-Karama have been placed in provisional detention in connection with a military investigation, party head Seifeddine Makhlouf wrote on Facebook.

Israel's supreme court was holding a hearing Monday on the case of Palestinian families facing expulsion by Israeli settlers in annexed east Jerusalem, an issue that sparked conflict in May.

Iran on Monday vowed to respond to any "adventurism", its foreign ministry said, after the U.S. and Britain joined Israel in blaming Tehran for a deadly tanker attack, claims it denies.

The MT Mercer Street, managed by prominent Israeli billionaire Eyal Ofer, was attacked on Thursday off Oman.

Israel's key allies the United States and Britain joined it Sunday in blaming Iran for a deadly tanker attack off Oman, despite Tehran's denials, and Washington vowed an "appropriate response".

The U.S. and British statements came after Israeli Prime Minister Naftali Bennett said there was "evidence" linking Iran to the attack after the Islamic republic rejected its arch-foe's "baseless accusations".

Hamas leader Ismail Haniyeh has been re-elected unopposed, officials confirmed Monday, furthering his grip over the Palestinian Islamist group that controls the Gaza Strip after recent clashes with Israel.

In a statement, Hamas said that its electoral process had concluded with his reappointment as political chief after "tens of thousands" of members took part in the internal poll. 

Egypt's military said Sunday it has killed 89 suspected insurgents in operations in North Sinai, a region where an affiliate of the Islamic State group has been active for nearly a decade.

Israel's prime minister Sunday directly blamed Iran for a drone attack on an oil tanker off the coast of Oman that killed two people, making a veiled threat to retaliate as Tehran denied being involved in the assault.

The comments by Premier Naftali Bennett and Iranian Foreign Ministry spokesman Saeed Khatibzadeh come after the strike Thursday night on the oil tanker Mercer Street. The attack marked the first-known fatal attack after years of assaults on commercial shipping in the region linked to tensions with Iran over its tattered nuclear deal.

Israeli Prime Minister Naftali Bennett on Sunday denounced the painting of swastikas on a synagogue near Tel Aviv, calling it a "grave act of hatred".