New Delhi, May 4 -- US stock futures turned volatile on Monday, 4 May, after conflicting reports surrounding a US warship near the Strait of Hormuz heightened investor anxiety over the ongoing Middle East conflict.

Futures tied to the S&P 500 were down 0.4%, while those linked to the Nasdaq-100 traded flat. Dow Jones Industrial Average futures, meanwhile, were down 0.1%.

Iran's semi-official Fars news agency reported on Monday that two missiles had struck the US warship near the port of Jask, located at the southern entrance to the strait, where Iran's navy maintains a base.

"The Islamic Republic of Iran has repeatedly announced that any passage through the Strait of Hormuz is not possible without obtaining official permission from Ira...