Pakistan's president narrowly escaped an apparent assassination attempt on Sunday when a bomb exploded seconds after his convoy passed by.
Musharraf tightened his security after previous assassination attempts
President Pervez Musharraf was returning to his official residence near Islamabad when the bomb went off, damaging a bridge.
The president said he was certain he was the target.
Three men were jailed in October for a failed attempt on the president's life last year.
No-one was hurt in Sunday's blast, which happened in the northern Pakistani city of Rawalpindi.
The president had come from the city's airport after a visit to the southern city of Karachi.
"When I came back from my tour of Sind and as I was going home from Chaklala (airbase) and we crossed the Ammar Chowk Bridge, there was an explosion just half a
minute or one minute after we crossed," Mr Musharraf told Pakistani television.
"I felt the explosion in my car. That is all that I know, except, of course, that
it was certainly a terrorist act and certainly it was me who was targeted. "
No one has claimed responsibility for the blast, and officials say it is too early to blame any particular group. A high-level investigation has been launched.
The explosion came on the same day that Indonesian President Megawati Sukarnoputri arrived in Pakistan for a three-day visit during which she is expected to sign an anti-terrorism pact. She is due to meet Mr Musharraf on Monday.
There has been at least one previous attempt to assassinate the Pakistani leader, who came to power in a bloodless coup in 1999, and who has been a key support of the US-led war on terror.
In April 2002, a car packed with explosives failed to detonate as President Musharraf passed on a busy road in Karachi. In October, three men were each sentenced to 10 years in jail over the plot.
The same car was used in the June 2002 attack outside the US consulate in Karachi in which 12 Pakistanis, were killed, police said.