BOGOTA, Colombia (AP) _ The government lifted a nighttime curfew in the cocaine center of Medellin on Wednesday, saying the city was back to normal after nearly a month of drug- related shootings, bombings and arson attacks.

Medellin Mayor Juan Gomez said there was no more need for the 11 p.m.-5 a.m. curfew, which was imposed Aug. 30 in the city of 2 million.

On Tuesday night, gunmen attacked the Medellin home of federal Judge Laurentino Gallego Gil but police guards drove them off, police said. One guard was wounded, a Medellin police spokesman said on condition of anonoymity.

Earlier Tuesday, hundreds of mourners attended the funeral of former Medellin Mayor Pablo Pelaez Gonzalez, who tried to rid the city of drug traffickers. Pelaez was assassinated on his way to work Monday.

The mayor said the city has returned to ''absolute normalcy,'' although army vehicles remained on the streets.

There are some exceptions to the lifting of the curfew.

Motorcycles, frequently used in drive-by bombings, are banned from the streets from 6:30 p.m.-5 a.m. Restaurants, bars, discos and other places of entertainment must close at midnight during the week and 1 a.m. Friday and Saturday.

In Bogota, the 13th Army Brigade on Wednesday displayed weapons captured in a raid just north of the city. The chief Defense Ministry spokesman, Col. Eduardo Arevalo, said the guns probably belonged to drug traffickers.

Authorities displayed about 20 semiautomatic and automatic arms, including Israeli Galil, U.S. R-15, Chinese AK-47 and Belgian FAL rifles; a British MP-5 machine gun; and pistols, grenades, ammunition and radio scanners for monitoring police and military frequencies.

The Bogota newspaper El Espectador said the cache, seized Tuesday, belonged to Gonzalo Rodriguez Gacha, the reputed No. 2 member of the Medellin drug cartel. The Defense Ministry spokesman did not confirm that.

Colombia has offered a $250,000 reward for information leading to the capture of Rodriguez Gacha or reputed cartel leader Pablo Escobar.

It declared a war on the country's drug lords Aug. 18 after a leading presidential candidate was assassinated.

In the Brazilian capital of Brasilia, an Aeronautics Ministry communique said Wednesday that Brazil's air force has moved a powerful, 54-ton mobile radar unit to the jungle border wih Colombia to detect clandestine flights by drug traffickers. It said the unit has a 125-mile range and can pick up several planes simultaneously.

Romeu Tuma, Brazil's federal police chief, has ordered border controls tightened to prevent Colombian drug traffickers from sneaking into Brazil. Although not a major cocaine producer, Brazil is considered an important cocaine processing and transshipping point and as a hideout for traffickers.

At Meech Lake, Quebec, Chris Davis, a spokesman for Prime Minister Brian Mulroney, said Canada has conveyed to Bogota ''an acceptance in principle'' of Colombian proposals for Canadian help in its drug fight, with details and cost to be worked out.

Colombia also is at war with guerrilla factions.

In northern Cesar state, troops killed 12 leftist guerrillas, an officer said Wednesday.

Col. Tobias Duran Quintanilla, the regional military commander, said in a radio interview the battle Tuesday was with guerrillas of the Revolutionary Armed Forces of Colombia, the largest of six rebel groups. He gave no details.

In a guerrilla-stronghold in Cauca state, police Wednesday prevented 7,000 Indians from marching to Popayan, the regional capital. Two Indians were wounded in a clash with police, RCN radio reported.

The station said Guanbiano and Paeces Indians, protesting the recent killings of two Indian activists, announced they were on a hunger strike and took over a highway leading to Popayan.

About 75,000 Colombians have been killed in the past 25 years in guerrilla fighting and other politically motivated conflicts.

At a rural encampment in southwestern Colombia, the government continued talks with the second-largest guerrilla group, M-19, aimed at working out a truce or amnesty.