JERUSALEM – Two rockets crashed into open desert areas in southern Israel, the military said Saturday, causing no damage or injuries.

It was not immediately clear from where both rockets, which landed some 100 kilometers (60 miles) apart, were launched. But the incidents raised concern over increasing militant activity in Egypt´s neighboring Sinai peninsula which has seen growing lawlessness following the uprising last year that overthrew Hosni Mubarak.

Palestinian militants in the Gaza Strip have fired thousands of rockets in recent years at Israeli communities on its border. But the rockets, which landed late Friday, were found in areas far from Gaza, sparking speculation that they may have been fired from Sinai.

A spokeswoman for the Israeli military declined to say from where the rockets were launched and said that their origin was being investigated. She spoke on condition of anonymity in line with military regulations.

She said remnants of both rockets were discovered Saturday and that the military was alerted after explosions were heard late Friday.

In April, Israel accused militants operating in the volatile Sinai peninsula of lobbing a rocket that slammed into the southern resort town of Eilat, which also caused no injuries. Egypt denied that claim.

Last August, gunmen from Sinai sneaked into Israel and ambushed vehicles on a desert highway, killing eight Israelis. Six Egyptians were killed in Israel´s subsequent hunt for the militants, causing a diplomatic crisis that ended with an Israeli apology.

That incident suggested that Gaza militants with their allies in Sinai were exploiting Egypt´s political turmoil to open a new front against Israel.

Sensing the growing threat, Israel has increased its surveillance on the Egyptian border and is building an electronic barrier along the 230 kilometer (150 mile) frontier in a bid to keep out militants and illegal migrants. (© 2012 The Associated Press 06/16/12)