Foreign Secretary Philip Hammond has condemned the actions of a "few individuals" who targeted the Serbian leader at an event to mark the 20th anniversary of the Srebrenica massacre.
Aleksandar Vucic was forced to flee as people pelted him with water bottles, stones and other missiles.
Hammond said: "I deplore the way a few individuals have sought to ruin the solemnity of today's commemoration.
"Their action should not be allowed to detract from the sentiments felt by a majority; that the countries and peoples of the western Balkans need to move forward together in reconciliation and co-operation."
The 1995 massacre of 8,000 Muslims by Bosnian Serb forces was the worst since the Holocaust.
Serbia's interior minister has condemned what he described as a "scandalous attack" on the country's prime minister after he was chased from a Srebrenica ceremony.
Aleksandar Vucic left the event after he was targeted by angry crowds throwing stones and bottles.
"This is a scandalous attack and I can say it can be seen as an assassination attempt," Nebojsa Stefanovic said on Serbian Pink television.
"Bosnia has failed to create even the minimal conditions for the safety of the prime minister", he added.
Serbian Prime Minister Aleksandar Vucic was forced to leave an event to mark the 20th anniversary of the Srebrenica massacre today after being chased away by a crowd hurling stones and bottles.