A shadowy new pro-government force has been deployed in the embattled Yemeni port city of Aden, according to reports Sunday, sparking speculation that ground troops from the Saudi-led coalition may have joined the battle against Houthi rebels and their allies.

Saudi Arabia, however, denied that it had sent ground forces to Aden or any other part of Yemen.

The deployment of Saudi troops in Yemen would mark a major escalation in the war. […]