The French capital's Place de la Republique has reopened after it was evacuated following the discovery of a suspicious package. Europe has been on high alert since the attacks in Paris, in which 130 people were killed.

The eponymous metro station has also been closed and verifications on the nature of the package are under way, Liberation has reported. The metro lines 3, 5, 8, 9 and 11, which go pass Place de la République station had been partially suspended.

European capitals on highest level of terror alert

The Belgian capital's streets were eerily quiet as the city was on lockdown. Authorities are still warning of possible imminent attacks like those in the French capital. They are searching for Brussels barkeeper Salah Abdeslam, who returned to the city from Paris hours after the attacks on 13 November.

On 23 November, French President Francois Hollande vowed to intensify strikes against Islamic State (Isis) in Syria and Iraq amid a renewed international focus in the wake of the attacks. British Prime Minister David Cameron met Hollande in Paris on the same day to discuss the fight against terror and how to cooperate on counter-terrorism.

"We are convinced that we need to continue to strike Daesh [Islamic State] in Syria," Hollande told reporters at a press briefing. "We will intensify our strikes and we will chose targets that will yield maximum destruction to that terrorist army and our aircraft carrier that is about to arrive on the zone has been clearly mandated to strike Daesh hard."

French warplanes struck their first targets in Syria in late September. Hollande added: "We need to coordinate our efforts on an external level. The United Kingdom, like France, participates in the coalition [efforts] in Iraq and we try and make sure that our strikes are the most useful. Yet, we also need to act in Syria."

Cameron said the world was coming together to fight IS, and said it was his firm conviction that the UK should join air strikes in Syria but that the decision would be up to MPs. He added: "We have discussed how we can further strengthen our counter-terrorism co-operation between our two countries and work together to defeat Isis in Iraq and Syria."