Belgian PM calls for solidarity as Europe reels from 'day of tragedy'

European leaders expressed shock and condemnation as countries across the continent stepped up security after two deadly bombings shook Brussels on Tuesday morning.

In a press conference, Belgian Prime Minister Charles Michel said that many people had been killed and wounded in the attacks targeting the Belgian capital's main airport and a metro station.

"What we feared has happened," said Michel, calling for "calmness and solidarity".

"We must face up to this challenge by coming together and being united."

Speaking on Belgian television later in the day, Michel said: "This is a day of tragedy, a black day."

A tearful Federica Mogherini, the EU foreign policy chief, appeared in a joint press conference with Jordanian Foreign Minister Nasser Judeh in Amman and called for a united front against such attacks.

"Being here together is the most powerful message of strength and friendship among our people that we can pass to those who would like to divide us," she said.

"We are united in not only suffering... but also reacting to these acts and preventing radicalisation and violence together."

Various European leaders called emergency crisis meetings following the attacks, and stepped up security in and around transportation hubs.

Three of Belgium's neighbouring countries, France, Germany and the Netherlands imposed heightened security arrangements at borders, airports and rail stations.

French President Francois Hollande, who called an emergency meeting of his senior government ministers, said that the whole of Europe had been hit by the attacks.

'We are at war," he told reporters. "We have been subjected for the last few months in Europe to acts of war."

As an act of solidarity, the Eiffel Tower in Paris will be lit up in the colours of the Belgium flag.

In the UK, Prime Minister David Cameron called a meeting of the COBRA emergency response committee and said the country would do everything it could to help.

“I am shocked and concerned by the events in Brussels,” Cameron tweeted as security at UK airports was stepped up and Eurostar trains through the Channel tunnel to Belgium were cancelled. The UK's threat level was increased to "severe", meaning that the probability of an attack is considered likely.

Spanish Prime Minister Mariano Rajoy said: "Terrorism will never defeat us. The union of democrats in Europe will always prevail over barbarism and madness."

Mark Rutte, the Dutch prime minister, also called a ministerial crisis committee meeting for his government to discuss the attacks.

“Our hearts go out to the victims and next of kin,” he stated. “The Netherlands stands ready to help and support our southern neighbours in any possible way.”

Describing the attacks on Belgium’s capital as “cowardly and murderous,” Rutte stressed that heightened security alertness was crucial not only in Belgium but surrounding countries.

Germany’s Justice Minister Heiko Maas said that “the horrible events in Brussels affect us all”.

“Today is a black day for Europe,” Heiko said. “We are steadfastly at the Belgians’ side.” 

Trump says close borders

Meanwhile, the White House tweeted President Obama's statements on the attacks, which he called "outrageous".

US Republican presidential candidate Donald Trump also weighed in with his own views on the attacks. 

“I would close up our borders,” Trump told Fox News. “We are taking in people without real documentation. We don’t know where they’re from or who they are."

          Do you all remember how beautiful and safe a place Brussels was. Not anymore, it is from a different world! U.S. must be vigilant and smart!

— Donald J. Trump (@realDonaldTrump) March 22, 2016

In the US, New York and Washington DC also stepped up security, deploying elite counter-terrorism reinforcements to crowded areas and train stations, police said.

Russian President Vladimir Putin condemned the attacks, and declared that terrorism knew no borders.

“The fight against this evil implies most active international cooperation,” he said.

Afghan President Ashraf Ghani was also quick to denounce the attacks.

Egypt's foreign ministry posted a message of solidarity on its official Facebook page, echoing sentiments of solidarity with the victims and condemnation of the attacks.

"Foreign Ministry spokesperson Ahmed Abu Zeid reiterated Egypt's position that asserts that brutal terrorism does not differentiate between religion or race, and knows no boundaries," the post read.

"Egypt is confident that the Belgian government will do all it can to uncover the circumstances surrounding these unfortunate incidents and bring the perpetrators to justice." 

Turkish Prime Minister Ahmet Davutoglu, whose country has suffered a string of recent bombings in Ankara and Istanbul, said the attacks "have once against shown the worldwide character of terrorism." 

Lebanon's Shia militia group Hezbollah issued a statement condemning "takfiri terrorist groups" and their "black venom" ideologies.

"Terrorism needs to be confronted with courage, seriousness, full regional and international cooperation, and a clear transparent policy," the statement said.

There was no immediate claim of responsibility for Tuesday's attacks. They came days after Salah Abdeslam, a key suspect in last November's Islamic State (IS) group-claimed attacks in Paris, was shot and arrested in the city.