SANA, Yemen — A Saudi-led military coalition bombarded government buildings and residential neighborhoods in Sana, the Yemeni capital, overnight on Saturday, killing more than two dozen people, officials and witnesses said, and destroying homes in Sana’s Old City, a Unesco World Heritage site.

The Saudi coalition, which includes nine other Arab nations and is supported by the United States, began fighting Yemen’s Houthi rebels in March, two months after the Houthis drove the government from power and took control of Sana. Coalition warplanes have sharply intensified their bombing of Sana in recent weeks, leading analysts to speculate that the airstrikes are intended to ease the way for a coalition ground incursion of the capital.

The airstrikes hit the headquarters of the Interior Ministry and a military honor guard, killing at least 17 security and military personnel, according to government officials and witnesses. But several of the targets appeared to have no military value, witnesses said.

One set of airstrikes crushed a group of houses, killing at least 10 members of one family and destroying at least two other houses, all in the Old City, which has been inhabited for more than 2,500 years.

Other bombs struck an underpass, damaging a passing truck, as well as a four-story residential building.

The aerial campaign has helped coalition forces advance in parts of Yemen, but has been marked by a persistent imprecision that has led to the deaths of more than a thousand civilians, according to human rights groups. The warplanes have bombed homes, markets, refugee camps and hospitals, but the coalition has consistently refused to acknowledge any culpability for the deaths.

In Their Own Words

Children are terrified by noises. Finding food is a challenge. There’s rarely power. Many people in Yemen and beyond dream of an end to the fighting.

The Many Miseries of Yemeni FamiliesMARCH 1, 2015