ADEN, Yemen, July 13 (Xinhua) -- Yemen's internationally recognized government on Monday evening reopened the country's airspace and resumed civilian flights after a temporary closure imposed amid escalating tensions over an Iranian aircraft carrying a senior Houthi delegation.

The Yemeni Transport Ministry said precautionary measures had been lifted and flights to and from government-controlled airports had resumed, with airlines expected to gradually restore scheduled operations in line with approved flight plans.

Meanwhile, the United Nations (UN) urged restraint as tensions mounted. "I am deeply concerned about the risk of wider escalation," UN Special Envoy for Yemen Hans Grundberg said in a statement.

The envoy said his office was engaging with all parties and military representatives to facilitate de-escalation, urging them to "refrain from any actions that would risk a new cycle of violence in Yemen" and return to dialogue under UN auspices.

Earlier on Monday, Yemeni authorities suspended civilian air traffic and temporarily closed government-held airports as security tensions escalated.

The closure came after the Yemeni Armed Forces said they had struck the runway of Sanaa International Airport to prevent an Iranian passenger plane carrying a senior Houthi delegation from landing in the Houthi-controlled capital. The aircraft later landed at Hodeidah International Airport in western Yemen, according to local sources.

The Houthi group accused Saudi Arabia of carrying out the strikes, while its military spokesperson Yahya Sarea said the attack had ended a period of de-escalation and "will not go unanswered."

Later in the day, a spokesperson of the coalition forces for Yemen said Saudi air defenses responded to a "threat" involving ballistic missiles launched by the Houthi group toward the kingdom's southern region.

Separately, the Yemeni government accused the Houthi group of detaining an aircraft operated by the International Committee of the Red Cross (ICRC) at Sanaa International Airport, preventing it from departing and holding its pilot and co-pilot.

In a statement, Yemeni Information Minister Muammar al-Eryani described the alleged incident as "a dangerous escalation" and "a blatant violation of international humanitarian law and conventions." He called on the ICRC, the UN and the international community to press for the immediate release of the aircraft and its crew.

Responding to Xinhua's request for comment, Hisham Mhanna, spokesperson for the ICRC in Yemen, said all personnel were safe but declined to comment further.

"All ICRC staff and the crew of the plane are safe and accounted for. We will not be providing further comment at this stage," Mhanna told Xinhua.

The Houthi group had not publicly responded to the government's allegations regarding the ICRC plane.

Monday's developments marked one of the most serious confrontations over access to Houthi-controlled airports since a UN-mediated truce expired in late 2022, raising fresh concerns about the durability of the de facto ceasefire between the government and the Houthis despite sporadic clashes on several front lines.

Yemen has been mired in conflict since late 2014, when the Houthis seized control of the capital, Sanaa, prompting a Saudi-led coalition to intervene the following year in support of the internationally recognized government.