Increased Hamas presence on main roads of the Palestinian enclave after two bombings target security forces.

The Gaza Strip is in a “state of alert” after explosions killed three policemen in the Palestinian enclave in apparent suicide attacks.

The police officers died in “two explosions targeting police checkpoints” late on Tuesday, the interior ministry in the Hamas-controlled coastal territory said in a statement.

Such attacks on Hamas, which has the most powerful armed apparatus in the enclave, are rare.

An interior ministry spokesman, Eyad al-Bozom, said security forces were making progress in their pursuit of those behind the explosions, but he did not disclose further details.

“The sinful hands that carried out this crime will not escape punishment,” said al-Bozom.

The first blast destroyed a motorcycle as it passed a police checkpoint, witnesses said. Two police officers were killed and a third Palestinian was wounded. It was not immediately clear if the riders were among the casualties.

The second explosion, less than an hour later, killed one officer and wounded several people at a police checkpoint elsewhere in the city, the interior ministry said.

Hamas chief Ismail Haniya said Gaza can “absorb” such incidents.

“We are certain, things will be controlled and all sides involved in these bombings will be held accountable,” he said in a statement.

Hamas – which took over Gaza in a 2007 civil war with the forces of Palestinian President Mahmoud Abbas – has at times faced internal opposition from more hardline fighters aligned with al-Qaeda or the Islamic State of Iraq and the Levant (ISIL or ISIS) group.

Escalating violence

A source familiar with the investigation told AFP news agency a group in Gaza that sympathises with ISIL was suspected.

Hamas and Islamic Jihad condemned the attacks.

“These events only serve the Israeli occupation, which tried to stab the Palestinian resistance in the back. What the occupation could not achieve by launching wars on Gaza will not be achieved by such bombings,” said Hamas spokesman Fawzi Barhoum.

Meanwhile, the Popular Front for the Liberation of Palestine (PFLP) blamed Israel for the bombings.

The Israeli military said it was unaware of any action in the Gaza Strip.

Earlier on Tuesday, the Israeli military had bombed a Hamas military post after fighters in Gaza fired a mortar round across the separation fence but said it hadn’t carried out any air raids at night.

Tuesday’s events were the latest in a string of incidents that have raised concerns of further escalation before Israel’s September 17 elections.

Israeli Prime Minister Benjamin Netanyahu is fighting for re-election, with political opponents calling for tougher action against Hamas.

On Monday, Israeli warplanes hit what the military said were “terror targets in a Hamas military compound in the northern Gaza Strip, including the office of a Hamas battalion commander”.

Israel also announced it was slashing by half the fuel it pipes to Gaza’s main power station, meaning a cut to the region’s already meagre electricity supply.

Wars on Gaza

Israeli authorities have accused Hamas of being responsible for the latest violence, which undermines a truce brokered by the United Nations and Egypt that provides for an easing of the Israeli blockade of Gaza in return for an end to military operations from the Palestinian enclave.

Specifically, the Israeli army accuses Hamas of not doing enough to contain its ally, Islamic Jihad, which is considered close to Israel’s foe, Iran.

Since 2008, Israel has waged three wars on the Gaza Strip, killing thousands of people, mostly Palestinian civilians.

Israel has long held Hamas responsible for violence from Gaza, while Hamas says Israel is responsible for the state of anger and pressure inflicted on Gaza’s residents because of the continued siege.

The Gaza health ministry said since the start of the weekly Great March of Return protests last year, the Israeli army has killed more than 300 demonstrators and wounded 17,000 others.

Seven Israelis have also been killed.