UN Secretary General Antonio Guterres warned Monday that the destruction of the vital Yemeni port of Hodeida could trigger a "catastrophic" situation, after at least 149 people were killed in heavy clashes.

Secretary of State Mike Pompeo told Saudi Crown Prince Mohammed bin Salman on Sunday the US will hold accountable all those involved in the killing of a dissident Saudi journalist, in a telephone call that also took in the conflict in Yemen.

British foreign minister Jeremy Hunt held talks Monday with Saudi King Salman, state media said, during a visit to press the kingdom over journalist Jamal Khashoggi's murder and the escalating Yemen war.

A clash that erupted during an Israeli special forces operation in the Gaza Strip and killed eight people threatened on Monday to derail efforts to restore calm to the Palestinian enclave after months of unrest.

At least 149 people including civilians were killed in 24 hours of clashes between government loyalists and rebels in Yemen's flashpoint city of Hodeida, medics and military sources said Monday. 

Israeli Prime Minister Benjamin Netanyahu has said he was unaware of any corruption linked to a deal to buy German submarines, after police recommended charging his lawyer in the investigation.

Fighting for control of Yemen's rebel-held city of Hodeida reached residential streets on Sunday, as the Huthi insurgents mounted fierce resistance to government forces backed by Saudi Arabia, military sources said.

Israeli Prime Minister Benjamin Netanyahu has defended his decision to enable Qatar to bring $15 million into Hamas-controlled Gaza for salaries, saying it would calm tensions and prevent a Palestinian humanitarian crisis.

Jihadists have killed at least eight Syrian government troops near a planned buffer zone around the country's last major rebel bastion, a monitor said on Saturday.

Airstrikes by Saudi Arabia and its allies in Yemen are on a pace to kill more civilians than last year, according to a database tracking violence in the country, despite the United States' repeated claims that the coalition is taking precautions to prevent such bloodshed.

The database gives an indication of the scope of the disaster wreaked in Yemen by nearly four years of civil war. At least 57,538 people — civilians and combatants — have been killed since the beginning of 2016, according to the data assembled by the Armed Conflict Location & Event Data Project, or ACLED.