The recent arrests of three alleged drug gang leaders from Mexico and the shooting of a sheriff's deputy in South Texas are raising fears among some Lone Star State officials that the brutal drug wars plaguing Mexico are taking hold north of the Rio Grande. On Sunday, Deputy Hugo Rodriguez of Hidalgo County in the southern tip of Texas was shot several times when he pulled over a vehicle containing a person kidnapped by members of Mexico's Gulf Cartel, County Sheriff Lupe Trevino said. Rodriguez's bulletproof vest saved his life, Trevino said. "I have always said we have never reported spillover violence, but I have to say that this particular incident is our first example," Trevino said. Trevino said cartel leaders told members to enter the United States to search for marijuana stolen from the cartel. The Mexican gang used members of a Texas-based street gang, mostly illegal immigrants, to seek out the drugs, Trevino said. And three alleged high-ranking leaders of the Gulf Cartel have been arrested in Texas in the past two weeks after seeking refuge in the United States in the aftermath of internal gang warfare, according to federal court documents released this week. "Amazingly, these individuals are using Texas as a safe haven to protect themselves from the very violence that they have created," U.S. Senator John Cornyn, a Republican from Texas, told reporters this week. The internal warfare was sparked by the September murder in Mexico of Samuel Flores Borrego, a top Gulf Cartel leader, according to the court documents. His death has led to a power struggle between two factions of the Gulf Cartel. DRUG ARREST Rafael Cardenas Vela, 38, the nephew of a co-founder of the Gulf Cartel, was arrested October 21 in Port Isabel, Texas, according to U.S. Immigration and Customs Enforcement. He is charged with conspiracy to possess and distribute drugs and using a fraudulent passport. Two other Gulf Cartel members, Eudoxio Ramos Garcia and Jose Luis Zuniga Hernandez, have been arrested in Texas in the past week, according to ICE. All three arrests are related to the split in the Gulf Cartel, said Scott Stewart, vice president of tactical intelligence for the Austin-based private intelligence firm STRATFOR. "The friction between two parts of the Gulf Cartel has been brewing for the past couple of months, and now it appears it is breaking out into all out war," Stewart told Reuters on Thursday. "It is quite possible that the information that led to Cardenas' arrest was actually leaked to U.S. authorities by his rivals in the cartel." Texas Attorney General Greg Abbott on Wednesday wrote in a letter to President Barack Obama that the three arrests and the shooting of the deputy show that the administration is failing to secure the border. "I implore you to aggressively confront this escalating threat," Abbott wrote. A call to the White House press office was not immediately returned on Thursday. Monica Weisberg-Stewart, a McAllen business owner and the chairwoman of the security committee of the Texas Border Coalition, said incidents like the ones from the past two weeks aren't new in South Texas. "There is still less crime down here on the border than there is in most parts of the country," said Weisberg-Stewart, whose coalition includes elected officials and business owners. "What we need is to work on establishing a true sense of security, and not take reactive steps, which will give us a false sense of security."