The son of Yemen's powerful Islamist Al-Islah (Reform) party's secretary general was seriously wounded when his father's car exploded in Sanaa on Tuesday, a security official told AFP.

"Omar Abdelwahab al-Ansi was critically wounded" in the explosion, the security official said.

The blast came shortly after unidentified gunmen in the capital shot dead a law professor who has been representing Shiite Huthi rebels at Yemen's thorny reconciliation talks.