Survivors of the Bali bombings and families of victims braved a fresh terrorism threat today to remember those killed in the terror atrocity.

Security was tight for the occasion a decade after bombs destroyed a holiday in paradise for tourists partying at two nightclubs near the beach in Bali.

More than 2,000 police and military, including snipers, were deployed to guard the memorial service after reports involving the "certain movement" of terrorists were announced two days earlier.

The 2002 bombing was Asia's deadliest terror strike, killing 202 people - including 28 Britons, 88 Australians and seven Americans - and injuring more than 240 on Indonesia's resort island.

The attack, carried out by the al Qaida-linked Jemaah Islamiyah group, started a wave of violence in the world's most-populous Muslim nation that hit an embassy, hotels and restaurants.

Some members of Jemaah Islamiyah were convicted over the bombings and three were executed by firing squad in 2008.

The security alert was raised to its highest level but no other details were released about the potential threat.

"The loss is not just giving us grief, it is also giving us the strength to fight terrorism and all other extremist activities," said Bali governor Made Mangku Pastika, the former police chief who led the investigations following the attacks.

Most of Indonesia's 210 million Muslims practice a moderate style of Islam that condemns violence, and the government has worked to root out extremists.

Terrorist attacks aimed at foreigners have been largely replaced in recent years by smaller, less deadly strikes mostly targeting police and anti-terrorism forces.

Data from the National Police shows more than 700 militants have been arrested over the past 10 years, including 84 last year. Dozens more have been killed since the Bali bombings.

Though the number of domestic terrorist attacks has risen, suicide bombers are more likely to act alone or in smaller groups than they did in years past.