Two explosions shook a southern Israeli city near Egypt on Wednesday, and the military suspected a cross-border rocket attack though searches have thus far turned up no evidence.

The blasts took place in the town of Eilat after darkness fell. Tensions have been running high in neighbouring Sinai where Egyptian troops have mounted a sweep after a deadly August 5 attack on a security post by militants who then stormed Israel's border.

There were no reported casualties in Wednesday's incident. "We suspect there was a possible rocket attack," a military spokeswoman said, though searches for explosive remains turned up no results. Searches were expected to resume at daybreak.

Islamist militants were suspected to be behind an increasing number of rocket attacks at Israel from Egypt.

The last such attack on June 16 also caused no casualties. Israel said it has since moved in an Iron Dome missile interceptor system to protect the region.

The violence has challenged a 1979 peace accord whose durability has already been tested by the toppling of Israeli ally Hosni Mubarak last year and his latest succession by Muslim Brotherhood leader, Mohammed Mursi, who has pledged to abide by the treaty with Israel which his movement has long opposed.

(Writing by Allyn Fisher-Ilan; Editing by Jackie Frank)