A trash scavenger was seriously wounded by a hand grenade explosion in central Bangkok in the wee hours of Friday morning, police said, marking the second blast in less than a week.

Meanwhile, an appeals court granted bail Friday for a leader of antigovernment protest group charged with terrorism in connection with fierce antigovernment demonstrations that crippled the Thai capital earlier this year.

Police said the modified hand grenade was left among garbage bags opposite a downtown duty-free shopping complex near Victory Monument, apparently on purpose.

The city's garbage collectors were scheduled to pick up the trash shortly after the trash scavenger, a man in his 30s, was searching in it.

The man, whose identity was not immediately known, was hospitalized in critical condition,

The explosion came just hours after the government decided to retain the state of emergency imposed in Bangkok and nine other provinces, while lifting it in six other provinces.

Prime Minister Abhisit Vejjajiva imposed the state of emergency on April 7 in 24 provinces to control the antigovernment protests organized by the United Front for Democracy against Dictatorship (UDD), which comprises supporters of ousted Prime Minister Thaksin Shinawatra.

The two-month-long protests, which crippled the capital, ended May 19 when troops forcibly removed the protesters encamped in the Ratchaprasong area of central Bangkok.

Last Sunday, an explosion occurred at a bus stop outside a combination discount store and food outlet in the Rajaprasong area, killing one person and injuring eight.

The appeals court Friday released on bail Veera Musikapong, a UDD leader, while prohibiting him from leaving the country or taking part in any large gatherings.

Veera is regarded as one of the UDD leaders who opposed violent confrontation with the government and who tried to compromise with it during the mass street protest in which almost 90 people died and 1,900 were injured. Other UDD leaders remain in jail.