Matamoros residents are on edge after enduring two days of gun battles that paralyzed several areas of the city.
The first gun battle took place outside the Chedraui supermarket off Calle Sexta in the downtown area of Matamoros on Tuesday evening.
Another round of violence with blockades and shootouts was reported in different areas of the city on Wednesday.
No group has claimed responsibility for the violence while Mexican authorities have not released any information.
But the American Consulate in Matamoros issued alerts on Twitter and its website.
The consulate asked Americans to remain indoors while the violence was taking place.
Security Message for U.S. Citizens " Report of Numerous Security Incidents- August 8, 2012
The Consulate General in Matamoros has advised its staff to remain indoors until further notice due to ongoing security incidents in Matamoros. A gunfight was reported in west Matamoros as well as numerous roadblocks throughout the city.
For the latest security information, U.S. citizens traveling abroad should regularly monitor the Department's internet web site at http://travel.state.gov where the current Worldwide Caution, Travel Warnings, and Travel Alerts can be found. Up-to-date information on security can also be obtained by calling 1-888-407-4747 toll free in the United States and Canada, or, for callers from Mexico, a regular toll line at 001-202-501-4444. These numbers are available from 8:00 a.m. to 8:00 p.m. Eastern Time, Monday through Friday (except U.S. federal holidays).
Please review the Department of State TMs Travel Warning concerning travel within Mexico and the state of Tamaulipas, available at http://travel.state.gov/travel/cis_pa_tw/tw/tw_5665.html. The Department continues to advise U.S. citizens to defer non-essential travel to the state of Tamaulipas. We also encourage U.S. citizens living or traveling abroad to register with the nearest U.S. Embassy or Consulate through the State Department's travel registration web site at https://travelregistration.state.gov/ibrs/ui/ so that they can obtain updated information on travel and security. Americans without internet access may register in person or by phone with the nearest U.S. Embassy or Consulate. By registering, American citizens make it easier for the Embassy or Consulate to contact them in case of emergency.
For any emergencies involving American citizens in the Matamoros consular district, please call or visit the American Citizens Services (ACS) Unit at the U.S. Consulate General on Avenida Primera 2002, Col. Jardin, Matamoros, Tamaulipas; telephone (011)(52)(868) 812-4402; http://matamoros.usconsulate.gov/.