SANAA, Yemen (AP) — Yemeni peace talks in Switzerland were halted on Friday after the country's Shiite rebel delegation suspended all meetings with the internationally recognized government in protest over its cease-fire violations, members of Yemen's two warring sides told The Associated Press.

The rebels, known as Houthis, said they would not resume talks unless the U.N. condemned the breaches by government forces of the week-long truce, the delegates said. Houthi fighters have also ignored the cease-fire agreement.

But the United Nations, which is mediating the talks, cast doubts on the alleged suspension.

"In my latest meeting with the heads of delegations, they all renewed their commitment for a ceasefire," the U.N. special envoy for the country, Ismail Ould Cheikh Ahmed, tweeted Friday evening.

The deputy spokesman for the U.N. secretary-general, Farhan Haq, told the AP that the U.N. had no confirmation of any suspension of talks and that Ahmed "remains in touch with the parties."

The U.N. later said Ahmed "held several sessions with the participants on the fourth day of the peace talks." Its statement also said Ahmed was "deeply concerned at reports of violations of the cessation of hostilities announced earlier today."

The U.N. has urged all factions in the conflict to end the violence and is pressing to keep the talks going. The Houthis appeared to be tactically stalling to avoid meeting their obligations under a deal reached with the government a day earlier, government delegates told the AP.

On Thursday, the Houthis agreed to permit the resumption of humanitarian aid deliveries into the besieged city of Taiz and to exchange prisoners, including the government's Defense Minister Mahmoud al-Sabahi — concessions they were reluctant to make.

The war in Yemen pits the Houthis and army units loyal to former President Ali Abdullah Saleh against pro-government forces, which are backed by a U.S.-supported, Saudi-led coalition, as well as southern separatists, religious extremists and other militants.

The peace negotiations began Tuesday at the Swiss Olympic House in the village of Macolin, a training center for elite athletes. Police armed with automatic weapons patrolled outside the facility, which was cordoned off with metal barriers requiring journalists to keep about 50 meters (yards) away.

The U.N. mediator has sought to keep a lid on communications about the goings-on inside — with mixed results. Officials have never fully acknowledged the location of the talks, and Ahmad Fawzi, a U.N. spokesman in Geneva, has said participants signed a "non-disclosure" agreement pledging not to speak to the media until they were over.

On the ground, fighters from both sides are refusing to respect the cease-fire, security officials neutral in the conflict said.

A member of the Houthi delegation said that U.N. envoy Ahmed had "promised to condemn the government and then he did not."

"They are using the cease-fire as an excuse although they were the first to break it," a government delegate said.

The officials spoke on condition of anonymity in line with regulations.

__

Associated Press writers Jamey Keaten in Geneva and Cara Anna at the United Nations contributed to this report.