(Updates with details of damage from Guerrero government)
By Dave Graham
MEXICO CITY, April 18 (Reuters) - A powerful earthquake shook Mexico on Friday, damaging more than 100 homes in the southwestern state of Guerrero and opening cracks in some buildings but there were no reports of deaths.
Striking close to the popular beach resort of Acapulco, the 7.2 magnitude quake sent people scurrying out of homes and hotels, causing brief panic from the Pacific coast to states in central and eastern parts of Mexico.
At least 127, mostly adobe homes were damaged in Guerrero. In the state capital Chilpancingo, a tower of the cathedral suffered cracks along with a few other public buildings, a spokesman for local emergency services said.
But there were no reports of deaths or major damage.
Some people in Mexico City fled homes in panic when the quake hit. Electricity was cut off in parts of the city and some residents said paintings fell off the walls, while small parts of masonry crumbled inside apartment buildings.
"I had to hold on to a tree, like a drunk," said Pedro Hernandez, 68, a doorman working in central Mexico City.
The U.S. Geological Survey (USGS) said the earthquake's epicenter was about 37 km (23 miles) north of the municipality of Tecpan de Galeana in Guerrero, and it struck at the relatively shallow depth of about 24 km (15 miles).
Lasting more than a minute, the quake was felt as far away as the states Puebla and Tlaxcala in central eastern Mexico.
It also caused some minor landslides and damaged a bridge on the road between Acapulco and the resort of Zihuatanejo to the northwest, emergency services in Guerrero said.
State oil giant Pemex said its refineries and other installations were operating normally after the tremors.
An employee of the Fairmont hotel in Acapulco, said the situation was calm and that guests quickly returned to the building after the quake struck on Friday morning.
"The structure is fine," the woman, who identified herself only as Ana, said by telephone.
Cesar Sanchez, 24, a student living in Chilpancingo, said he got a big shock when the quake started.
"I was in bed, and some things fell that have never fallen. The dogs outside were barking and barking," Sanchez said.
A devastating 8.1-magnitude earthquake in 1985 killed thousands of people in Mexico City. In March 2012, a 7.4 magnitude quake hit Mexico but did not cause major damage. (Additional reporting by Michael O'Boyle, Gabriela Lopez, Anahi Rama, Sandra Maler and Noe Torres; Editing by Kieran Murray)