A convoy of heavily armed gunmen launched an attack on a senior Mexican state prosecutor, then continued to toss grenades and shoot at police in a midnight chase though Villahermosa, the capital of the Gulf state of Tabasco. Tabasco state Deputy Attorney General Alex Alvarez was not hurt inside his armored vehicle, but a bystander was killed and 13 other people were injured, including six police, authorities said Thursday. Alvarez said his four bodyguards were seriously injured in the attack in Villahermosa, a city of about 330,000 people.