Israel launched a series of strikes in Gaza on Sunday in response to attacks on its forces, the military said, shaking an already fragile ceasefire in the shattered enclave as it traded blame with militant group Hamas for violating the truce.

Residents in Gaza and local health authorities said that Israeli airstrikes and tank fire across the enclave killed at least 11 people.

An Israeli military official said that further strikes against Hamas targets may still be launched, in retaliation for at least three attacks on Israeli troops on Sunday.

The Israeli military said that airstrikes and artillery fire targeted militants in the southern area of Rafah who had launched an anti-tank missile and fired on its soldiers.

Prime Minister Benjamin Netanyahu said that he had ordered the military to respond forcefully to what he described as Hamas' violations of the ceasefire.

Hamas' armed wing said in a statement that it remained committed to the ceasefire agreement in all of Gaza, adding that it was unaware of clashes in Rafah and that it has not been in contact with groups there since March.

The flare-up was the most serious test yet to the Gaza ceasefire, which took effect on October 11 halting two years of war and further dimmed hopes that the US-mediated truce would lead to a lasting peace.

Defense Minister Israel Katz said the "yellow line" to where Israeli forces had pulled back under the ceasefire agreement would be physically marked and that any violation of the ceasefire or attempt to cross the line would be met with fire.

The Israeli government and Hamas have been accusing each other of violations of the ceasefire for days.

Hamas issued a statement detailing what it said were a series of violations by Israel, that it said have left 46 people dead and stopped essential supplies from reaching the enclave. (Reuters)