A vendor was killed by a hand grenade in a busy market in the Yemeni capital of Sanaa on Monday, police source said. The old man was selling lighters when a hand grenade exploded, a police officer told Xinhua, adding that no other casualties were reported. Witnesses said the man was shouting angrily before the grenade exploded, saying that his 20-year-old son was shot dead by Saudi Arabia border forces when he tried to cross the border to find a job. The police official said the man was a resident near Habra market. There are more than 60 million pieces of weapon in the possession of citizens in Yemen which has about 24 million population, according to local media. Weapons are traded freely in the country where strong tribes own grenades, missiles and even tanks.