Saudi Arabia beheaded Wednesday two of its nationals for murder and a third for drug trafficking, bringing to 107 the total number of executions this year, according to the interior ministry.

Turki al-Diaini, convicted of shooting dead another Saudi, was put to death in Riyadh, while Sharie al-Jineibi was executed in southwestern Asir region for a shooting death.

A Saudi lawman was killed and two others were wounded during an attack in a Shiite-dominated area of Eastern Province, the interior ministry said Wednesday.

"One policeman was killed and two injured," an interior ministry spokesman said.

A humanitarian truce in Yemen has failed to take hold after Saudi-led warplanes resumed raids Tuesday on rebels, who clashed with loyalists, military sources said.

Iran, which backs the Shiite Huthi rebels, accused its Sunni regional rival Riyadh of "playing with fire and with the ceasefire".

Saudi Arabia beheaded one of its citizens for drug trafficking on Tuesday, in the second execution after a pause for Ramadan.

Saif al-Hadissane was found guilty of smuggling a large amount of hashish.

Human Rights Watch condemned as an "apparent war crime" on Tuesday a Saudi-led air raid in Yemen last week that it said killed at least 65 civilians in residential compounds.

The New York-based watchdog charged that the Saudi-led coalition had failed to investigate alleged breaches of the rules of war during the bombing campaign it launched against Shiite rebels in March and called for a U.N. probe.

Saudi King Salman has expressed support for Turkey after it launched air strikes against the Islamic State group in Syria and Kurdish militants in Iraq, state media reported on Tuesday.

The king told President Recep Tayyip Erdogan on Monday that he backed Turkey's right to self-defense, the official Saudi Press Agency said.

Saudi Arabia's foreign minister on Monday denounced "aggressive statements" by Iran, after Tehran accused Saudi ally Bahrain of stoking Gulf tensions by making unfounded allegations against it.

"This is unacceptable to us," Foreign Minister Adel al-Jubeir said at a joint news conference with visiting EU foreign policy chief Federica Mogherini.

Saudi-led coalition warplanes on Monday hit positions of pro-government forces in south Yemen by mistake, killing 12 people on the first day of a humanitarian truce, Yemeni military sources said.

The raids targeted positions in Lahj province, where Saudi-supported loyalists have been tightening the noose on Iran-backed Shiite Huthi rebels, the sources said.

EU foreign affairs chief Federica Mogherini held talks in Saudi Arabia Monday to explain the agreement she helped broker on Iran's nuclear program, and to push for an end to Yemen's war.

Mogherini met with Foreign Minister Adel al-Jubeir in the latest visit by a top Western official aimed at easing Saudi concerns over the deal with its regional rival.

The Saudi-led coalition fighting rebels in Yemen suspended its air war Monday to allow desperately needed aid deliveries, although clashes broke out in several areas despite U.N. calls for a truce.

The Huthi Shiite rebels, who control swathes of Yemen including the capital Sanaa, said they had not been consulted about the unilateral coalition ceasefire that began at midnight (Sunday 2100 GMT).