In a brazen daytime attack, about a dozen Islamic militants robbed a local bank, lobbed grenades and traded gunfire with security forces guarding an unused church in Egypt's Sinai Peninsula on Monday, killing seven people, including three civilians, officials said.

The militants drove into the city center of el-Arish in the morning, then split into two groups. One group traded gunfire with the guards outside the Church of Saint George, security and military officials said. Services at the church were suspended months ago, following a wave of attacks on Christians in Sinai.

The church attack was meant as a distraction from the bank, where the second group of militants first shot and killed the bank guards, then stormed in and emptied its safe. The heavy security and military forces deployed in the city put up little resistance.

The attacks left three civilians, including a child, three guards and one soldier dead and wounded another 15 people, including women and children, the officials said.

The two groups of attackers were caught on camera while fleeing the site of the clashes in a stolen pickup and three motorcycles.

"They looted the entire bank and left explosive devices inside," a senior security official said. All officials spoke on condition of anonymity because they were not authorized to talk to reporters.

Egypt's state news agency MENA confirmed that three policemen were killed in an armed attack on the bank in el-Arish.

Panic spread in the city, which has been under a state of emergency and curfew since a series of deadly IS attacks in 2014. A bank employee appeared to have been kidnapped in Monday's attack, the officials said.

Security forces cordoned off the city center and evacuated residents living in the bank building. Pictures posted on social media by locals from el-Arish showed school girls fleeing a school located in the vicinity of the bank and the church.

Schoolteacher Ashraf Hanafi told The Associated Press that the gunfire lasted for about two hours on Monday morning.

"I rushed to my daughters' school," he said, adding that on his way he saw militants brandishing rifles and running toward the bank. He said he also saw bodies of two bleeding men lying on the ground.

The fighting came less than 24 hours after the Islamic State affiliate in Sinai killed nine soldiers in series of attacks targeting checkpoints across the nearby town of Sheikh Zweid. IS claimed responsibility in a statement carried by the extremists' Aamaq media outlet. The army said 24 attackers were killed. On Thursday, six other policemen were also killed in an attack by the militants in el-Arish.

Egypt has been struggling to combat an Islamic insurgency in the northern Sinai that gathered strength after the military overthrew of an elected Islamist president in 2013. The IS affiliate in Egypt has focused its attacks on Coptic Christians, the army and police. Thousands of Christian families have fled el-Arish, including Father Mikhail who said only 10 Christian families remain in the city.

The largest IS attack in Sinai came in 2015, when militants planted a bomb inside a Russian airliner that blew up over the peninsula after departing from the Red Sea resort of Sharm el-Sheikh, killing all 224 people aboard. It was also IS' largest single attack in Egypt to date.

St. George's in el-Arish was attacked twice previously, first during the uprising against longtime autocrat Hosni Mubarak in 2011, and again after the 2013 ouster of Islamist President Mohammed Morsi.

At the time, Father Mikhail said that attackers torched the church and looted everything inside, even the cables. He said the wardens only managed to rescue a few items, some icons and the church's most precious possession, the remains of St. George that were preserved inside the church.

Then last year, militants gunned down a priest from St. George's.

Sunday's attacks on military checkpoints prompted Egyptian authorities to postpone the opening of the Rafah crossing with Gaza, which had been due to open for four days. No new date has been set.

The uptick in violence comes at a time when Egypt and the Gaza Strip's ruling Palestinian militant Hamas group, have been making reconciliatory efforts, including the shutting down of underground tunnels used over the years to smuggle weapons, goods and militants to and from Gaza. Egypt has also mediated a reconciliation agreement between Hamas and it Palestinian rival, Fatah, which rules the West Bank.

The opening of the Rafah crossing was part of efforts to ease a decade-old Israeli-Egyptian blockade of the coastal territory.

Waging a two-hour attack in a busy street in the city center of el-Arish raised questions about a persistent security vacuum in the city and its surroundings, at a time the armed forces' claims of victory against militancy.

Issa Kharafeen, a tribal leader, said the attacks reflect how the military lacks good sources of information among the locals as IS has systematically hunted and gunned down informants.

"The security forces have lost the (source of) information," said Kharafeen, who himself fled el-Arish after receiving threats from IS over allegations he was cooperating with the army. "They are in need for eyes everywhere."