SAM Rainsy Party lawmaker Yont Tharo said yesterday that guards at the Vietnamese embassy in Phnom Penh had prevented him from delivering a letter calling on the Vietnamese government to investigate the killings of two Khmer Krom men in Tay Ninh province earlier this month. Yont Tharo, who himself is Khmer Krom, tried to give the letter to the embassy yesterday afternoon. The two deceased were involved in a violent altercation on September 2 that also resulted in five other injuries, according to the letter.