Four near-simultaneous small explosions went off in subway stations and outside a court building in Cairo on Wednesday, wounding three people and causing widespread panic among morning commuters, officials said, in the first attacks since the election of Egyptian President Abdel-Fattah el-Sissi.

Authorities quickly accused the Muslim Brotherhood of orchestrating the attacks, describing them as "desperate attempts" to disrupt the "prevailing state of stability." The group, to which the ousted President Mohammed Morsi belonged, has denied involvement in any violence. But even some Islamists warn that young Brotherhood supporters could turn to attacks under pressure of a fierce crackdown on the group for nearly a year.

Three of the blasts, caused by homemade explosive devices, went off in separate subway stations in central and northern Cairo, and the fourth was a bomb that had been planted under a car outside a courthouse in the upscale Heliopolis district, Interior Ministry spokesman Hani Abdel-Latif said. In one of the subway attacks, one of the injured was a man who carried the explosive in his backpack, Abdel-Latif said. In another, the bomb was hidden in a garbage can.

A total of three people were injured in the attacks, Abdel-Latif said.

Police quickly sealed off stations and used sniffer dogs to search for more explosives. Abdel-Latif said that other bombs were found and defused outside the court building and in a fourth metro station.

He called the attacks a "desperate attempt by the Muslim Brotherhood terrorist organization to prove they still exist."

No one immediately claimed responsibility for the attacks — the first in the Egyptian capital since last month's election of el-Sissi as the country's new president.

El-Sissi led the military's ouster of Morsi on July 3 after millions demonstrated against the Islamist president in the streets. Since then, Morsi's supporters have staged near-daily protests demanding his return to power. Such demonstrations have usually been met by a fierce police crackdown, often turning into clashes. Hundreds of Morsi supporters have been killed and thousands detained.

At the same time, Islamic militants have stepped up attacks against the military and police across Egypt. The government branded the Brotherhood a terrorist organization, saying it was behind the militant campaign, a claim the group denies.

An al-Qaeda-inspired group based in Egypt's Sinai Peninsula, Ansar Beit al-Maqdis, has claimed responsibility for most of the major attacks, including suicide bombings and attempted assassinations of top security officials. However, other groups believed to be connected to Morsi's supporters have claimed responsibility for smaller attacks, which have mainly targeted riot police heading to disperse protesters.

'Bullhorn diplomacy' won't work on Egypt, Baird says

The attacks come a day after el-Sissi said he won't interfere in the imprisonment of Egyptian Canadian Mohamed Fahmy and two other Al-Jazeera journalists. 

The terrorism charges and sentences against Fahmy, Australian Peter Greste and Egyptian Baher Mohamed have been widely condemned as bogus.

The harsh sentences have been the subject of vocal condemnation by Australian and U.S. politicians, but some critics say the Harper government is too muted in its response.

Foreign Affairs Minister John Baird defended the government on Tuesday, saying "bullhorn diplomacy" won't win the men's release.

Canada is pursuing all legal avenues to secure the release of Fahmy, the minister told Ottawa radio station CFRA.

The government is working hard to have Fahmy freed on appeal, or through a possible presidential pardon, Baird said.

"We want a successful resolution and I guess either way, critics of the government can win because if we're loud and vocal, we're practicing bullhorn diplomacy and are not being professional," Baird said.

Mideast Egypt Al Jazeera

Canadian-Egyptian journalist Mohammed Fahmy was sentenced to seven years in an Egyptian prison on terrorism-related charges. Foreign Affairs Minister John Baird said "bullhorn diplomacy" won't win Fahmy's release. (Ahmed Abd El Latif/El Shorouk/Associated Press)

"But if we try to take the case directly to the leadership, we're accused of not standing up. I think you want to pursue the path that would be the most effective to resolving the case."

Fahmy's family, the federal New Democrats and Canadian Journalists for Free Expression have all urged Prime Minister Stephen Harper to call the Egyptian president personally.

Australian Prime Minister Tony Abbott called el-Sissi to proclaim the innocence of the Australian journalist, while the country's Foreign Minister Julia Bishop said she was appalled by the severity of the verdict.

"I'll note that the Australian hasn't been released either," Baird said Tuesday.

'We're going to stay engaged'

Baird defended his junior minister, Lynne Yelich, who is responsible for consular affairs. She issued a news release Monday that was widely criticized because it merely said she was very disappointed with the sentence.

Yelich works hard and does a good job, Baird said, while his role as foreign minister is to make representations to his Egyptian counterpart, which he did on a visit to Cairo two months ago.

"We have many cases in Egypt of Canadians that are before the courts," Baird said without elaborating.

"When I met with the Egyptian foreign minister and had a long discussion of this case, they can't issue a presidential pardon unless there's a verdict, and until the appeals are exhausted, so obviously we're going to stay engaged with this file, with this case," Baird said.

Baird also confirmed that he and his deputy minister called in Egypt's ambassador on Monday and issued a formal diplomatic protest.

Baird said Fahmy's case is complicated by the fact that he is a dual Egyptian and Canadian national and also by the intertwined relationship between Al-Jazeera, its Qatari ownership and Egypt's banned Muslim Brotherhood.

Fahmy and his two co-accused were convicted of giving a voice to the Islamist Muslim Brotherhood, which Egypt has labelled a terrorist group. They were accused of harming Egypt's national security.

The journalists deny the charges, and say they were only doing their jobs.

"One of the challenges of this case is that Al-Jazeera is, of course, funded by the government of Qatar, who is also directly funding the Muslim Brotherhood, and that's what makes this case more complex and adds a different dimension to it," said Baird.

He added: "I don't think anyone believes he's in cahoots with the Muslim Brotherhood, but obviously the government of Qatar had a close relationship."

With files from The Canadian Press