Less than three weeks after Yemen's government reached a truce with a group of Shiite rebels known as Houthis, a suicide bomber on Thursday killed at least 47 people at an anti-government demonstration of Houthi supporters in Tahrir Square in the Yemeni capital of Sanaa.

Another suicide attack on the same day killed at least 20 soldiers at a military checkpoint outside the southern port city of Mukalla. It was the second straight day of militant violence in the country. On Wednesday, assaults against several government and security offices killed at least 29 people.

The bloodshed highlights the country's worsening political situation, which has deteriorated since Houthi militants won control of Sanaa in September. Weeks of fighting between the Houthis and the Sunni-dominated government left more than 140 people dead prior to the signing of a UN-brokered peace deal on September 21.

Thursday's rally in Sanaa was organized to protest President Abd-Rabbu Mansour Hadi's nomination of Ahmed Awad bin Mubarak as prime minister to form a new government, as stipulated by the peace deal. Mubarak had rejected his nomination ahead of the demonstration.

Under the peace deal's terms, the Houthis agreed to withdraw rebels from Sanaa and other cities in Yemen's north and surrender their weapons to the government within 45 days, but armed Houthi rebels were still in Sanaa on Thursday.

No group has yet claimed responsibility for the suicide bombings, but news reports point to the suspected involvement of al Qaeda in the Arabian Peninsula (AQAP), a branch of the terror group that has promised to defend Sunnis from the Houthis.

Yemeni officials blamed AQAP for Wednesday's attacks on security and government offices.

Houthi supporters were gathering for a march in Tahrir Square when Thursday's attack took place. Video captured immediately after the explosion showed victims — including children — missing limbs and lying in puddles of blood in the heart of the square.

Security camera footage showing the moment a suicide blast detonated in the Yemeni capital Sanaa was broadcast on Al-Masirah TV on October 9.

Shortly after the bomb went off in Sanaa, a suicide bomber drove a vehicle packed with explosives into an army checkpoint on the outskirts of the southern city of Mukalla, according to Yemeni security officials. In addition to the servicemen reported killed, the attack also destroyed a tank and two army vehicles.

"The Yemeni people have lived with senseless violence for far too long and the recent increase in hostilities against innocent civilians only undermines the progress Yemen has made since the 2011 revolution," the US Embassy in Yemen said in a statement. "Yemen's challenges are political and therefore must be resolved through political solutions. We call upon all parties to refrain from violence, to return to peaceful expression of dissent, and work through democratic means to make their voices heard."