On 23 October 1856, the British destroyed four barrier forts. On 25 October, a demand was made that the British be allowed to enter the Canton. The next day, the British began to bombard the city, firing one shot every 10 minutes. Ye Mingchen issued a bounty on every British head taken. On 29 October, the Royal Navy blasted a hole in the poorly defended and inadequate city walls. The troops entered Canton, with the flag of the United States being planted on the walls and residence of Ye Mingchen by James Keenan, the U.S. Consul. Losses were three killed and 12 wounded. Negotiations failed and the city was bombarded. On 6 November, 23 war junks attacked and were destroyed. There were pauses for talks, with the British bombarding at intervals, causing fires. On 5 January 1857, the British returned to Hong Kong.

On 3 March 1857, the British government lost a Parliamentary vote regarding the Arrow Incident and what had taken place at Canton to the end of the previous year. This defeat led to a general election in April 1857 which increased the government's majority.

In April, the British government asked the United States of America and Russia if they were interested in alliances, but both parties rejected the offer. In May 1857, the Indian Mutiny became serious, British troops destined for China were diverted to India, which was considered the priority issue.