(CNN) -- In a sign that the use of more sophisticated weapons may become routine in Mexico's war against the drug cartels, officials in Ciudad Juarez, Mexico, were studying an explosive projectile launched at federal police Sunday night during a shootout.
Video from the scene showed a small blast emanating from a device shot at the officers. The blast caused no major damage.
"There was an explosive projectile launched at the federal police. We do not know if it was a grenade or another type of explosive device. They launched it from a far distance," federal police spokesman Ramon Salinas told CNN.
The blast didn't cause as much damage as a regular grenade would, he said.
Still, the launching of the explosive device was a reminder of the capabilities of the drug gangs.
In a show of increasing sophistication, a car bomb exploded last month in Juarez, killing four. It was the first attack of its kind in the city.
Juarez is a flashpoint in the Mexican federal government's fight against the cartels. Hundreds of people have been killed this year in clashes between rival cartels or between police and cartels.
Also Sunday night, there were several armed conflicts reported between federal police and gunmen. Six people involved in the shootouts were in grave condition and six more were injured, Salinas said. One police officer was killed, he said.
CNN's Nick Valencia contributed to this report.