By Ahmed al-Masri

RIYADH/SANAA

Leaders of a Saudi-led Arab coalition fighting the Shia Houthi group in Yemen announced late Monday that Saudi forces had intercepted a "ballistic missile" fired from Yemen into the kingdom’s territory, according to the official Saudi Press Agency (SPA).

In a statement cited by the news agency, coalition commanders said they would "reconsider the policy of self-restraint that has been applied since the ceasefire went into effect [in Yemen] in April".

They also vowed to take "all measures necessary to defend the sovereignty" of Saudi Arabia in light of Monday’s alleged missile attack.

This was the second ballistic missile fired into Saudi territory by the Houthis and their allies (forces loyal to former President Ali Abdullah Saleh) that the coalition claims to have intercepted since the April ceasefire went into effect.

According to the coalition statement, the missile was intercepted by Saudi air-defense forces late Monday, with coalition forces responding by destroying the launch pad in Yemen from which the warhead was fired.

Earlier Monday, Yemen’s Houthi-run SABA news website quoted a pro-Houthi military source as saying that Houthi fighters and pro-Saleh forces had targeted Saudi Arabia’s southwestern Najran province.

Meanwhile, Ismail Ould Cheikh Ahmed, the UN’s envoy to Yemen, said that intransigence by both sides of the conflict had led to "continued deadlock in the political and security files" at peace talks currently underway in Kuwait.

According to the Houthi-affiliated Al-Masirah television channel, Houthi and pro-Saleh representatives recently told Kuwait’s foreign minister that ongoing airstrikes by the Saudi-led coalition against Houthi positions in Yemen were damaging the prospects for a successful outcome of the talks in Kuwait.

 Prisoner swap

In a related development Monday, representatives of Yemen’s warring camps exchanged lists of prisoners in advance of a proposed prisoner swap.

According to Yemeni government sources who spoke on condition of anonymity as they are not authorized to speak to media, the proposed swap -- if approved by both sides -- will be implemented on Friday or Saturday.

The government’s list includes the names of 2,630 people believed to be held by the Houthis (including Yemeni Defense Minister Mahmoud al-Sobeihi and the brother of President Abd Rabbuh Mansur Hadi), while the Houthi list includes the names of 3,000 people thought to be held by pro-Hadi forces, the same sources said.

Yemen has been racked by violence chaos since late 2014, when the Houthis and pro-Saleh forces overran capital Sanaa and several other parts of the country.

According to UN figures, the conflict has since led to the death of more than 6,400 Yemenis and forced some 2.5 million to flee their homes.

UN-brokered negotiations between the Yemeni government led by President Hadi and the Houthis and their allies kicked off in Kuwait City on April 11.