Israeli Prime Minister Benjamin Netanyahu threatened Tuesday to teach Gaza's ruling Hamas movement a lesson "very soon" following a surge in militant rocket attacks on the Jewish state.

"We have a very clear policy. We prevent terror attacks when we identify them in the making, and we respond forcefully against whoever hurts us," Netanyahu told reporters at a press conference with visiting Canadian counterpart Stephen Harper.

"This policy produced a quiet year in 2013, which was the quietest in many years. If Hamas and the terror organisations have forgotten this lesson, they will learn it again powerfully very soon."

His warning was issued shortly after Hamas said it had deployed forces in Gaza to "preserve the truce" following an uptick of rocket fire on Israel.

Over the past month, tensions have risen in and around Gaza after more than a year of relative calm following a major Israeli confrontation with Hamas in November 2012.

Since December 20, four Palestinians and an Israeli have been killed in violence in and around Gaza, with militant rocket fire sparking retaliatory air strikes by Israel.

Army figures show eight rockets have struck Israeli territory since January 1, and another five were intercepted by the Iron Dome anti-missile system, sparking fears that a new confrontation with Gaza militants is looming.

Netanyahu has warned that Israel would not allow the intermittent rocket fire to turn into a deluge.

"Security requires constant maintenance which means we don't accept what I call the 'drip irrigation' of rockets without a response - that is not the policy of this government," he told foreign reporters in an address on January 16.

"My government's policy is to respond so we don't let the drizzle of rocket accumulate into rain, which then develops into a storm. We act."

Earlier, Hamas confirmed its security forces had fanned out along the frontier to put a halt to firing by various militant groups.

"National security forces have been deployed in order to preserve the truce," Hamas interior ministry spokesman Islam Shawan told AFP, referring to an Egyptian-brokered deal which ended the last major confrontation with Israel.

Militants fired at least one rocket at southern Israel late on Monday which caused neither casualties nor damage.

Another rocket at the weekend prompted an air strike on Gaza City on Sunday, which wounded two Palestinians, one critically. The military said it had targeted a senior Islamic Jihad militant who was behind much of the rocket fire.