Thousands of protesters angry at a US-made anti-Islam film clashed with police close to Islamabad’s diplomatic enclave on Thursday in chaotic scenes that left at least 50 people injured.

Officers fired tear gas and live rounds as the demonstrators, many armed with wooden clubs, tried to reach the heavily-guarded enclave, home to most Western embassies, including the US, British and French missions.

The government called in the army to protect the area after protesters broke through a barrier of shipping containers set up by police to block a road leading to the enclave.

The crudely made Innocence of Muslims, produced by US-based extremist Christians, has triggered protests in at least 20 countries since excerpts were posted online, and more than 30 people have been killed in violence linked to the film.

The US state department on Thursday warned its citizens to avoid travel to Pakistan and Washington has moved to boost security at its diplomatic missions worldwide.

There have been dozens of demonstrations around Pakistan over the past week and at least two people have been killed, but Thursday was the first time protests in the capital had turned violent.

An initial demonstration of around 1,000 swelled to around 5,000 with the arrival of protesters carrying the flags of hardline Islamist groups Jamaat-ud-Dawa, Jamaat-e-Islami and Sipah-e-Sahaba— which is banned by the Pakistan government. Police fired tear gas and live rounds as the protesters, chanting “we are ready to die to safeguard the Prophet’s honour” and demanding punishment for those who insult Islam, stormed the container barrier.