SANAA - A powerful airstrike by Saudi-led coalition hit the headquarters of presidential office in the Yemeni capital Sanaa on Monday, targeting a secret meeting of Iranian-allied Shiite Houthi leaders and killing at least six, security sources at the scene told Xinhua.

"Top leaders, including President of Houthi Supreme Political Council Mahdi al-Mashat and Chief of Houthi Supreme Revolutionary Committee Mohammed Ali al-Houthi were believed to be at the meeting in the targeted president's office," a security source said on condition of anonymity.

He said six people were confirmed dead and up to 30 others were wounded.

Houthi-controlled state Saba news agency reported that dozens of peole were killed and injured in the airstrike that targeted the presidential office.

The office has been under Houthi control since the group forced the internationally recognized President Abd-Rabbu Mansour Hadi into exile in Riyadh, the capital of neighboring Saudi Arabia.

All roads around the office were closed and ambulances were seen carrying dozens of killed and injured.

The attack took place this morning, simultaneously with another airstrike on the headquarters of the Houthi-controlled Defense Ministry, about one km east of the president's office in Sanaa.

The attack is the second of its kind targeting top Houthi leaders in two weeks.

On April 23, the dominant Houthi rebels announced the death of their top official, President of the Supreme Political Council Saleh al-Sammad, saying he was killed in an airstrike by the Saudi-led coalition on April 19 in the Yemeni Red Sea port city of Hodeidah, according to a statement by Houthi-controlled Saba news agency.

The Houthis vowed to revenge al-Sammad's death, and they declared appointment of Mahdi al-Mashat to replace al-Sammad as new president of the Supreme Political Council, which is the highest political and ruling body since Houthis seized control over much of the country's north in late 2014.

If al-Mashat or Mohammed Ali al-Houthi were confirmed among the killed, it will be another powerful blow so far to the Iranian-backed Houthi movement.

The coalition intervened in the Yemeni conflict in March 2015 to roll back the Iranian-allied Shiite Houthi rebels and support the internationally-recognized President Hadi.

The rebels have seized control over much of the country's north since September 2014, including the capital Sanaa, and forced President Hadi and his government into exile in Riyadh, the capital city of Saudi Arabia.

The war has killed more than 10,000 Yemenis, mostly civilians, and displaced 3 million others, triggering one of the world's worst humanitarian crises.