Tensions between Iran and Saudi Arabia continued to escalate Saturday, with Iranian President Hassan Rouhani slamming Saudi-led airstrikes against Houthi rebels in Yemen.

"You planted the seeds of hatred in the hearts" of people in the region, said Rouhani at Iran's National Army Day ceremony, in comments directed at Saudi Arabia. "And you will see the response sooner or later," he added.

Iran's Supreme Leader Ayatollah Ali Khamenei previously called the Saudi-led campaign in Yemen a "genocide" and a "crime." Iran is believed to back the Shi'ite Houthi rebels with both military and financial support, but denies it.

Humanitarian assistance

Following more airstrikes Friday, Saudi Arabia pledged Saturday to provide the entire $274 million the United Nations requested for emergency humanitarian assistance in Yemen. The U.N. says at least 150,000 people have been displaced by the conflict, while more than 700 have died since the Saudi-led coalition began airstrikes three weeks ago.

"This contribution demonstrates the Kingdom's commitment to help the fraternal Yemeni people," an official statement quoted Saudi Ambassador to the United States Adel bin Ahmed Al-Jubeir as saying.

The Houthis took control of the capital, Sana'a in September. They then swept southward, forcing Western-backed President Abd-Rabbu Mansour Hadi to flee.

The rebels are allied with former Yemeni President Ali Abdullah Saleh, who was ousted as part of the so-called Arab Spring protests in 2012.

More here: Iran, Saudis on Collision Course over Yemen