A suicide bomber drove an explosives-laden car into a security building in the restive Sinai Peninsula on Monday morning, one day after 51 people were killed in Cairo in clashes that marred a national military holiday.

Gunmen also attacked a security convoy near the Suez Canal, killing six soldiers, and separate attackers launched a rocket-propelled grenade at the site of the country’s main satellite infrastructure, Egypt’s Interior Ministry said.

The resurgence of violence in Egypt, three months after a military coup ousted Mohamed Morsi from the presidency and two months after the new military-backed government launched a brutal crackdown to keep Morsi’s supporters off the streets, has underscored the likelihood of a continuing backlash.

The weekend’s clashes between security forces and anti-military protesters made Sunday the deadliest day this nation has seen since the government launched a crackdown on the Muslim Brotherhood, which backs Morsi, in August.

The Brotherhood-led Anti-Coup Alliance, which says it advocates peaceful protest, called on its supporters Sunday night to continue their demonstrations Tuesday and Friday.

But Monday’s attacks highlighted a growing willingness by some of the government’s opponents to use violence.

Since the coup, Islamist militants angered by Morsi’s ouster have launched near-daily attacks on security forces in the Sinai Peninsula, a mountainous region on Egypt’s border with Israel and the Gaza Strip.

Monday morning’s car bomb detonated outside a security headquarters in the south Sinai town of El Tor, killing three police officers and wounding 48, according to a statement by the Interior Ministry, which oversees the nation’s law enforcement agencies. The shrapnel from the blast tore open four floors of the building’s facade, Egyptian state television reported.

Egyptian Interior Minister Mohamed Ibrahim told the Associated Press in an interview that forensics teams were analyzing the body of a suicide bomber who had driven the car.

Two hundred miles to the northwest of El Tor, on a road branching away from the port city of Ismailia on Egypt’s vital Suez Canal, unidentified gunmen ambushed a convoy of troops traveling to a nearby garrison, the state news agency MENA said. The attack occurred near one of two gateways and the only bridge that connects mainland Egypt with the Sinai.

The Interior Ministry said in a statement that “unknown assailants also shot in the direction of the satellite station in Maadi, Cairo,” referring to the country’s main satellite receiver station in a southern neighborhood of the capital.

“One of the shots hit one of the satellites concerned with receiving broadcasts,” the statement said. The attackers had fired a rocket-propelled grenade at the satellite, MENA reported.

It was unclear if the three attacks Monday were related.

The Sinai blast struck near the southern tip of the peninsula, a vibrant expanse of turquoise coastline that has typically been more isolated from the violence in the peninsula’s northern region, and where government officials have sought in recent weeks to lure back tourists with promises of renewed security.

But the rash of violence Sunday and Monday appeared likely to derail the new government’s hopes of reviving Egypt’s tourism-dependent economy in the midst of its political crackdown.

“I think it’s incredibly worrying,” said Samer Shehata, an Egypt expert and political scientist at the University of Oklahoma.“How in the world are you going to encourage people to come back to Egypt and see the pyramids and the Valley of the Kings and bring in money if this is happening? How are you going to entice foreign direct investment if there is this kind of violence and perceived instability?”

There are lingering questions about the degree to which the Muslim Brotherhood is connected to the nation’s ongoing violence. The government has accused the group of terrorism and has imprisoned nearly all of the Brotherhood’s leaders on charges of incitement to violence or murder. The group says the charges are politically motivated, and Western diplomats and analysts have said there is no evidence tying the Brotherhood to terrorist attacks in recent years.

But the Sinai has presented a potential launch pad for a broader, nationwide insurgency, government officials, analysts and local Bedouin tribal leaders have said.

Poor, remote and neglected by successive governments, Sinai has become a hotbed for militancy and smuggling since the 2011 uprising that ended the 30-year reign of strongman Hosni Mubarak. Security officials and local residents say the area is awash with arms.

The unrest has alarmed neighboring Israel.

“Israel is following closely what is happening in Egypt, especially in Sinai, but it’s a delicate situation and Israel does not want to be pulled into any conflict,” said Aviv Oreg, a retired Israeli major general.

Lara El Gibaly in Cairo and Ruth Eglash in Jerusalem contributed to this report.