A Saudi-led military coalition trying to beat back an advance by Shiite rebels in Yemen denied on Tuesday that it has launched naval combat operations.
"We did not at any time mention that we have a sea operation, other than the control of the ports and the movement in the maritime zone around Yemen," Brigadier General Ahmed Assiri told reporters, referring to a maritime blockade.
Witnesses reported earlier that coalition naval forces shelled rebel positions in the southern port city of Aden.
The coalition has carried out nearly two weeks of air strikes in support of President Abedrabbo Mansour Hadi, who fled from Aden to the Saudi capital Riyadh late last month.
Western diplomats say Saudi Arabia has carried out most of the air strikes itself, aiming to defeat the Huthi rebels who seized power in the capital Sanaa in February.
The Huthis, allied with army units loyal to ex-president Ali Abdullah Saleh, are battling militia loyal to Hadi in a war which the International Committee of the Red Cross said has come to "every street" in Aden.
Assiri, however, said many parts of the city remained "stable".