The Chinese embassy in Britain on Thursday strongly condemned the despicable acts of separatist Hong Kong rioters who burnt the national flag and assaulted the embassy building.

In a statement on its website, the Chinese embassy said a dozen "Hong Kong independence" rioters set fire to the national flag of China on Thursday afternoon, in "blatant, flagrant and abominable" acts of vandalizing and insult in front of the embassy.

The rioters also assaulted the main gate of the embassy building and put up separatist slogans on the gate.

The rioters' actions amounted to grave desecration of the dignity of China and the nation, and violation of the Law of the People's Republic of China on the National Flag and the Law of the People's Republic of China on Safeguarding National Security in the Hong Kong Special Administrative Region, challenge to the sovereignty and territorial integrity of China and threat to the security and safety of the premises and staff of the Chinese embassy, said the statement.

The Chinese embassy expressed strong indignation and condemnation against such despicable acts. "These acts fully reveal the ugly nature of 'Hong Kong independence' elements as violent perpetrators and their true agenda of disrupting China and destabilizing Hong Kong," said the statement.

"The action of these rioters is against the will of the Chinese nation and will never succeed," it said.

The Chinese embassy said it has lodged solemn representation with the British police and the Foreign Office, urging the British side to make swift investigation and bring the perpetrators to justice at an early date.

The embassy also urged the British side to take concrete measures to fulfill its responsibilities and obligations under the Vienna Convention on Diplomatic Relations as the receiving state, safeguard the inviolability of diplomatic and consular missions, and ensure the security, safety and dignity of the premises and staff of the Chinese embassy and consulates-general in the country.