AL MUKALLA, Yemen — An airstrike launched by the Houthi faction in Yemen on Thursday killed at least 40 people, including a senior Yemeni military commander, at a parade in the city of Aden, officials said.

In a separate attack in the city, a suicide bomber drove a truck full of explosives into a police station, killing at least 11 people, officials said. There was no immediate claim of responsibility for that blast. At least 50 people were wounded in the two attacks in Aden, the provisional capital of the Saudi-backed forces in the country’s civil war.

The missile strike on the military parade was the bloodiest assault on the Saudi-backed forces and their territory since their other main external sponsor, the United Arab Emirates, announced a steep drawdown of troops last month.

The Emiratis had overseen security around Aden, and their withdrawal was also expected to remove portable Patriot missile batteries that they had deployed to help defend the city from such airstrikes. Although it could not be determined whether or not the Emirati missile defense system remained in place on Thursday, the death toll of the attack raised immediate concerns about other Houthi assaults or advances that might seek to take advantage of the Emirati withdrawal.