Hanoi last night warned that threats to Vietnamese inside Cambodia amid racially based electioneering could imperil regional stability.
The Foreign Ministry statement came as opposition figure Sam Rainsy conceded his recent speeches had raised fears among the troubled Vietnamese community and put relations with Vietnam at risk.
'All claims and acts against the overseas Vietnamese must be criticised, for they run counter to the agreements signed between the two states and are not beneficial to bilateral relations as well as the stability of Cambodia and the region,' a ministry spokesman in Hanoi said.
'They should have been respected and treated equally as other foreigners in keeping with international practices.' Vietnamese families are bracing for violence as opposition campaigning centres on old hatreds before the polls on July 26.
Opposition figures such as Mr Sam Rainsy, a prominent liberal, have been whipping up rural crowds by peppering speeches with the word yuon - a highly derogatory term for Vietnamese - in a bid to embarrass ruling Premier Hun Sen over his long links with Hanoi.
In a highly charged address dominated by racial references in Pailin last Friday, Mr Sam Rainsy's workers handed out leaflets reading: 'If you vote correctly, the yuon will go.' With Mr Hun Sen, Mr Sam Rainsy and opposition leader and former First Prime Minister Prince Norodom Ranariddh all set to campaign in the capital on Sunday, Vietnamese shopkeepers said they would take their families into hiding for the weekend and close.
'It seems the opposition aren't happy without blood,' one Vietnamese resident of Phnom Penh said as he tried to borrow money to send his children overseas.