SANAA, Yemen (AP) _ Saudi-led airstrikes targeting Shiite rebels and their allies destroyed historic houses in the Old City of the capital, Sanaa, a UNESCO world heritage site. At least five civilians were killed and others buried under the rubble, medical officials and witnesses said.

   Warplanes dropped missiles apparently targeting a house occupied by a senior rebel commander, witnesses said. The missiles didn't explode but their impact flattened at least three houses and caused cracks in surrounding buildings which are cemented to each other, leaving large sections of the district at risk of collapse.

   Online activists posted pictures from the damaged portion of the city, next to men digging for survivors from under the debris. Others circulated pictures from before the destruction to show the scale of damage to the complex of houses occupying a district in the Old City known as al-Qasimi _ one of the most popular and historic tourist attractions in the city.

   The Old City has been inhabited for more than 2,500 years. Decorated buildings are made of packed earth with burnt brick towers.

   In a statement from UNESCO, the agency's general director condemned the attack targeting ``the world's oldest jewels of Islamic urban landscape'' and expressing sorrow for the loss of lives.

   ``I am shocked by the images of these magnificent many-storied tower-houses and serene gardens reduced to rubble,'' Irina Bokova said in the statement and urged the warring parties to preserve the heritage of Yemen which ``bears the soul of the Yemeni people'' and ``belongs to all humankind.''

   UNESCO said that since the beginning of the conflict, several historic monuments across Yemen have suffered damage. It said that on June 9, the Ottoman era al-Owrdhi historical compound, outside the walls of the Old City, was severely damaged. 

   The Saudi-led coalition began conducting airstrikes on March 26 against Shiite rebels and their allies in the Yemeni security forces who had overrun the capital. The airstrikes, along with ground fighting between different warring parties, have killed 1,037 civilians, including 234 children, between mid-March and May and displaced more than a million people, according to U.N. estimates.