ISLAMABAD, Pakistan (CNN) -- Twin suicide bombers set off explosives at a naval college in Pakistan Tuesday, killing at least five other people and wounding at least 16, one critically, the government said.
Security officers prevented the two bombers from entering the Pakistan Navy War College in the eastern city of Lahore, according to a statement issued by the Pakistani military's Inter-Services Public Relations agency.
One of the explosions set off a chain reaction in a campus parking lot, with gas cylinders in nearby storage sheds exploding and cars powered by compressed natural gas catching fire, the ISPR said.
Interior Ministry spokesman Javed Iqbal Cheema said earlier a bomber had rammed his car into another vehicle, but the ISPR statement made no mention of the attackers using a car.
Lahore police told CNN five people had been killed in addition to the two bombers, and 16 were wounded. Local reports said 19 were injured.
Authorities immediately closed off access to the college and put the city on high alert, the Urdu language daily Jang reported. Watch aftermath of blast
The college, located in the busy center of Pakistan's second-largest city, trains senior naval officials from Pakistan and other countries.
Television footage showed a college gate blown apart. Black smoke billowed into the sky, while paramedics loaded bodies covered in blood-stained white sheets onto the back of trucks.
The attack took place on the same day the top U.S. military officer, Joint Chiefs of Staff Chairman Adm. Michael Mullen, met with Pakistani President Pervez Musharraf in Rawalpindi to discuss the security situation in the country.
Pakistan has experienced a wave of deadly attacks, most of them suicide bombings, that it blames on Islamic militants. Watch why this attack is significant »
There were at least four attacks in the four days leading up to the bombing at the naval war college. Four army personnel were killed in the bombing of a bus in Rawalpindi on Monday.
On Sunday, a suicide bomber detonated explosives at a gathering of tribal leaders in the North West Frontier Province, killing at least 30 people. The blast wounded another 25 people, officials in the area told CNN.
On Saturday, a suicide attack killed at least nine Pakistani security troops and wounded 11 civilians in the Bajaur district, the Federally Administered Tribal Areas (FATAs).
A day earlier, a suicide attack on the funeral of a district superintendent of police -- killed earlier in the day in a separate attack -- killed at least 11 people and injured 50 in the North West Frontier Province.
And on February 25, the army's top medical officer, Lt. Gen. Mushtaq Ahmad Baig, was killed in a suicide attack in Rawalpindi, where the army has its headquarters. E-mail to a friend