Grenade 'message' for Mexico

PLEASE NOTE: EDIT CONTAINS CONVERTED 4:3 MATERIAL
Two cars parked separate locations were targeted in grenade attacks in the Mexican state of Tamaulipas.
Nobody was hurt.
But authorities say the grenades were thrown to distract police while threatening anti-government messages were placed.
The content of the messages hasn't been revealed.
The first attack was on a car parked outside a prison.
The second vehicle to be targeted was in a public car park near a shopping centre and casino.
On the same day, in Mexico City, human rights activists took to the streets in protest against attacks on them by organised crime gangs.
The demonstration marked the anniversary of the murder of activist Marisela Escobeda.
She was gunned down on the steps of a court as she protested over the release of her daughters self-confessed killer.
SOUNDBITE: Lol Kin Castaneda, activist, saying (Spanish):
"She was demanding justice in the face of the liberation of the admitted murderer of her daughter Rubi Marisol. She demanded justice outside the State of Chihuahua court house. That's where she was assassinated. And one year later the reality is that is no clarity about the case. Her daughter's murderer remains a fugitive."
Mexico's government has vowed to prosecute those who attack activists but many remain unsolved.
A growing military presence across the country in Mexico's war against drugs cartels has also led criminals and authorities alike to seek to silence their critics.
Paul Chapman, Reuters