Brussels airport and Metro bombings Live updates

German federal police say they have stepped up security checks at the country's borders with Belgium, France, the Netherlands and Luxembourg.

Belgium’s prime minister, Charles Michel, said the terrorists had committed mass murder at the airport and metro stations, adding that military reinforcement have been deployed.

In a televised press conference, Michel confirmed the attack at the airport was carried out by a suicide bomber, and called for “calm and solidarity” after what he described as a “tragic moment.”

“I want to tell the Belgian people, and not only them, as there could be citizens of other countries who have died or suffered in these terrorists attacks, that we support them at this time. We have suffered a lot from terrorist attacks through all these years, and this is our common pain. We should defeat international terrorism no matter what, this should be our common goal. This is the time for us to unite in the struggle against international terrorism. We should join all our efforts, we should stand against this evil together to do everything we can to stop the spread of international terrorism not only in Europe, but all over the world,” the Russian Foreign Ministry spokeswoman, Maria Zakharova, told RT.

At least 15 people have been killed in the Metro terror attacks in Brussels, according to Belgian broadcaster RTBF. Ten more people have been reportedly injured. Earlier, the death toll from the Metro attacks and two airport blasts was estimated as at least 23 people.

A suspicious package has been discovered near Brussels Royal Palace,  RTBF reported.

European Council President Donald Tusk has called the Brussels attacks “another low by terrorists.”

“I am appalled by the bombings this morning at Zavantem Airport and the European district in Brussels which have cost several innocent lives and injured many others.

I extend my sincerest sympathies to the relatives and friends of the victims. These attacks mark another low by the terrorists in the service of hatred and violence...” he said in a statement.

A blast has been heard on a street where the Institutions of the European Union are located, potentially due to bomb technicians operating in the area.

Extra police will be deployed at key locations across the UK, according to Assistant Metropolitan Police Commissioner Mark Rowley.

“As a precaution forces across the UK have increased policing presence at key locations, including transport hubs, to protect the public and provide reassurance. This is not in relation to any specific information or intelligence,” he said in a statement.

French Prime Minister Manuel Valls has said that Europe is in a state of war, and that the terror threat is being constantly raised.