The spate of recent rocket attacks against Israel from Gaza are reportedly the result of increased tension between Hamas and extremist Salafist groups in the Strip.

According to a report Thursday in the pan-Arab daily Asharq al-Awsat, Hamas has arrested hundreds of Salafis in recent months, including noncombatants.

In order to put pressure on Hamas to release the prisoners, Salafi militants who identify with the Islamic State terror group and seek to turn Gaza into a caliphate have been firing rockets at Israel, which they know result in costly Israeli retaliations against Hamas property and sometimes its members.

Israel says it holds Hamas, the terror group that is the de facto ruler of Gaza, responsible for all attacks from the territory.

The report said that a few days ago, Salafis in Hamas jails began a hunger strike.

The past month has seen three rocket attacks from Gaza at Israel, including two this week. None of the attacks caused injuries in Israel, and no group has claimed responsibility for them.

Palestinians run for cover as sand and smoke rise following an Israeli airstrike on a Hamas post in the northern Gaza Strip on February 6, 2017. (Mohammed Abed/AFP)

Palestinians run for cover as sand and smoke rise following an Israeli airstrike on a Hamas post in the northern Gaza Strip on February 6, 2017. (Mohammed Abed/AFP)

After rockets landed in Israel on February 6 and again on February 27, Israeli aircraft and artillery pounded Hamas military sites.

Israel has yet to respond to the latest rocket attack, on Wednesday night.

A total of six Gazans were injured by the Israeli retaliatory attacks, according to the Strip’s Hamas-run health ministry.

The damage from Israel’s retaliatory attacks cost Hamas hundreds of thousands of dollars, according to the report.

The report said Hamas embarked upon its arrest campaign of Salafis in December in an attempt to stymie the flow of Gazan militants boosting the ranks of the Islamic State affiliate in the neighboring Sinai Peninsula.

The crackdown is reportedly being carried out at the behest of Egypt, which has been waging a years-long battle against the terror group. Around 550 men arrested for being affiliated with IS in the Sinai have been tried in Hamas military courts in recent days, and charged with firing rockets at Israel or with manufacturing weapons, according to the report.

The families of those Salafist detainees reportedly complained that the trials were simply a formality in order to allow Hamas to keep the detainees in prison.

Palestinian Salafis demonstrate in southern Gaza Strip, in September 2012 (Abed Rahim Khatib/Flash90)

Palestinian Salafis demonstrate in southern Gaza Strip, in September 2012 (Abed Rahim Khatib/Flash90)

Additionally, Hamas’s security forces are still searching for the man they believe is behind the most recent rocket attack Israel, Nur Issa, the leader of the IS-linked Salafi group Ahfad al-Sahaba. Issa’s group has claimed several rocket attacks against Israel since 2014.

Issa’s sister Nagham Issa complained over Facebook that her father and one of her brothers were arrested by Hamas in order to pressure her brother to turn himself in, the report said.

Issa reportedly appeared in a video recently criticizing Hamas over the crackdown on Salafis.

The recent rocket attacks against Israel aren’t the first time the conflict between Hamas and Salafis has spilled over into Israel.

A similar Hamas crackdown on Salafis in 2015 led the fringe groups to pressure Hamas by firing rockets at Israel, thereby breaking the calm that had existed since the end of the 2014 summer war between Hamas and Israel.

Salafist groups have created a headache for Hamas in recent years, accusing it of being too soft on Israel and of failing to adequately impose religious law.

However, some officials in Israel have also pointed to cooperation between Hamas and Salafi groups in Sinai, including Islamic State-affiliated fighters being smuggled into the Strip for medical care.

Analysts believe there are about 1,000 Salafi loyalists — too few to pose a threat to Hamas but enough to cause persistent problems.

Their preachers deliver anti-Hamas sermons, and Salafist fighters have claimed responsibility for numerous rocket strikes on Israel.

Hamas has generally tolerated the Salafists since they emerged in Gaza a decade ago, though there have been occasional confrontations. In 2009, Hamas killed a Salafi leader who declared an Islamic emirate in the southern city of Rafah. Since then Hamas has worked quietly to dismantle the groups.

AP contributed to this report.