Palestinian president Mahmud Abbas on Thursday slammed violence against civilians, including Gaza rocket fire after two projectiles hit Israel as US President Barack Obama visits.

"We condemn violence against civilians, whatever its source, including the firing of rockets," political adviser Nimr Hammad quoted Abbas as saying.

"We are for mutual and comprehensive pacification in the Gaza Strip, and we supported the agreement that was reached through Egyptian mediation on November 21, 2012," he added, referring to a ceasefire after eight days of conflict between Israel and Hamas militants.

Two rockets fired by militants in Gaza on Thursday hit southern Israel on the second day of a visit by Obama to the Jewish state.

Israeli officials pointed the finger at Islamist movement Hamas, a rival to Abbas's West Bank-based Palestinian Authority. Hamas implicitly denied responsibility, but gave a guarded reaction to Israeli accusations.

"Israel will be watching very closely president Abbas's remarks today in Ramallah to see if he condemns this morning's rocket attacks," a senior Israeli official told AFP earlier.

"Last year... he refused to condemn rocket attacks on Israeli civilians.

"We will also want to see if he ceases the unity talks with Hamas," he added, pointing out that the rockets came from Hamas-controlled territory.

Hamas said it "considers talk of rocket fire to be merely Israeli accusations aimed at gaining sympathy from Obama... and inciting him against Palestinians," its spokesman Sami Abu Zuhri told AFP.