Tunisian authorities have arrested an Al Jazeera reporter, the network's bureau chief said Thursday, as campaigners voiced concern over a growing number of journalists behind bars in the North African country.

"Samir Sassi, a journalist at the Al Jazeera office in Tunisia, was arrested after security forces raided his house" late Wednesday, said Lotfi Hajji, director of the Qatar-based television network's bureau in Tunis.

A "US strike" in Baghdad on Thursday killed a military commander of the Hashed al-Shaabi, the ex-paramilitary force said, with an Iraq security official reporting two deaths in a drone attack.

"A drone targeted the logistical support headquarters of Hashed al-Shaabi," mainly pro-Iranian former paramilitary units integrated into the Iraqi armed forces, said the security official.

U.S. Secretary of State Antony Blinken will head Thursday to the Middle East as fears mount that Israel's war in Gaza will spread across the region, following deadly blasts in Iran and the killing of a Hamas leader in Lebanon.

A U.S. official speaking on condition of anonymity confirmed the trip -- Blinken's fourth to the region since the start of Israel's war against Hamas in the Gaza Strip -- but declined to offer any details on the itinerary apart from a stop in Israel.

The United States has called on the U.N. Security Council to take urgent action against Yemen's Houthi rebels for attacking ships in the key Red Sea trade route and warned their longtime financier Iran that it has a choice to make about continuing to provide support to the rebels.

U.S. deputy ambassador Christopher Lu told an emergency council meeting that the Houthis have carried out more than 20 attacks since Nov. 19 -- and despite losing 10 fighters in a confrontation with U.S. forces after trying unsuccessfully to board a cargo ship on Sunday, the rebel group announced Wednesday morning they had targeted another container ship.

The killing of a top Hamas commander in an apparent Israeli airstrike on a Beirut apartment has given Israel an important symbolic achievement in its 3-month-old war against the Islamic militant group.

But history has shown the benefits of such dramatic operations are often short-lived, bringing on further violence and equally formidable replacements as leaders of militant groups.

Fears that Israel's war in Gaza could spiral across the Middle East have mounted after twin explosions ripped through an Iranian crowd, claiming at least 103 lives following a strike in Lebanon that killed Hamas's deputy leader.

More than 200 other people were wounded when the blasts about 15 minutes apart struck mourners commemorating slain Revolutionary Guards general Qasem Soleimani on the fourth anniversary of his killing in a United States drone strike, Iran's state media reported.

Israel's spy chief on Wednesday vowed to make Hamas pay for its attacks on Israel, after a drone strike attributed to Israel killed the group's deputy chief Saleh al-Arouri in Lebanon.

The Mossad spy agency "is committed to settling the score with the murderers who descended upon the Gaza envelope on October 7" and with Hamas' leadership, David Barnea said.

EU foreign policy Josep Borrell on Wednesday said the international community had to "impose" a solution to the conflict between the Israelis and the Palestinians.

"What we have learned over the last 30 years, and what we are learning now with the tragedy experienced in Gaza, is that the solution must be imposed from outside," Borrell told diplomats in Portugal.

France on Wednesday described as "provocative" comments made by Israeli ministers calling for Palestinians to emigrate from Gaza and Jewish settlers to return to the besieged territory.

"France condemns the comments of Israeli Finance Minister Bezalel Smotrich, and National Security Minister Itamar Ben-Gvir," the French foreign ministry said in a statement, after Ben-Gvir's statements on Monday and Smotrich's on Sunday. "We call on Israel to refrain from such provocative declarations, which are irresponsible and fuel tensions."

Yemen's Houthi rebels claimed responsibility for the latest attack Wednesday on a merchant ship in the Red Sea, as the vessel's operator sharply raised prices between Asia and Europe.

The Iran-backed rebels, who have launched more than 20 attacks on merchant ships in recent weeks, said they attacked the Malta-flagged freighter believing it was headed for occupied Palestinian territory. The ship was not hit.