Children among dead after airstrike in Yemen's capital

Seven children were among at least 16 people killed in an airstrike in Sanaa as suspected Saudi-led coalition raids continued to pound the Yemeni capital, the country's rebel-controlled health ministry said Friday.

The attack, which flattened two residential buildings in Sanaa's southern district of Faj Attan, comes amid escalating violence in the war-torn country.

A Saudi coalition spokesman told CNN that they were looking into the reports.

Saudi Arabia, backed by a coalition of Arab states, launched a military operation in March 2015 against Iranian-backed Houthi rebels who toppled the internationally recognized leadership in Yemen.

In the last week alone, the UN estimates that 58 civilians have been killed in airstrikes, including 42 in Saudi-led coalition bombings. That death toll is higher than the entire month of June, when 52 were killed, and in July, which saw 57 civilian deaths.

Since fighting began, the UN Human Rights Office has documented 13,829 civilian casualties, including 5,110 killed. The numbers, based on casualties individually verified by the UN's Yemen Office, are believed to be a fraction of the overall death toll.

Hotel attack

Friday's attack comes two days after an airstrike hit a hotel on the outskirts of Sanaa early Wednesday, leaving dozens dead.

The United Nations has launched an investigation into that attack. A witness told the UN that two airstrikes hit the area in close succession at around 3:30 a.m. The first struck a security checkpoint purportedly manned by Houthi rebels, and, several minutes later, a second strike hit the Istirahat Al Shahab hotel.

Mohammed al-Sarhi, a farmer, told CNN that most of those killed at the hotel died while sleeping and were buried under rubble.

The UN has confirmed that at least 33 civilians were killed and another 25 injured in the attack. Yemen's health ministry, which is controlled by Houthi rebels, says 51 people died.

The health ministry is based in Sanaa and is not part of the internationally-recognized, Saudi-backed government based in the southern city of Aden.

"We remind all parties to the conflict, including the Coalition, of their duty to ensure full respect for international humanitarian law," UN human rights spokeswoman Liz Throssell said Friday. "We call on the relevant authorities to carry out credible, comprehensive and impartial investigations into this incident."

Humanitarian crisis

Two-and-a-half years into its grinding civil war, Yemen is facing a near famine and one of the worst outbreaks of cholera in decades.

Last week, the World Health Organization reported that the number of suspected cholera cases in Yemen had reached 500,000 -- making it the largest cholera epidemic in the world.

Nearly 2,000 people have died since the cholera outbreak began to spread at the end of April, the WHO added.