Belgium upgrades terror threat level to 3 of 4
比利时恐怖威胁预警升级

Following the operation, police in Belgium have increased security outside their headquarters in Brussels. And the country has upgraded the national terror threat level to three from two on a four-point scale. Prime Minister Charles Michel says the raid shows the government's determination to fight those who want to spread terror.

"We are not aware of any specific or concrete threats, however in the situation we can consider it is useful to raise the level of prudence and vigilance. That concretely means that complementary measures of protection and security will be taken for evident reasons that we are not going to communicate," Michel says.